Binder resin composition for toner

ABSTRACT

Provided are a binder resin composition for toner excellent in low-temperature fusing property, storage stability and durability, a toner for developing electrostatic images that contains the binder resin composition for toner, and a method for producing the binder resin composition for toner. The binder resin composition for toner contains a resin composition (C-P) prepared by condensing an acid group-having crystalline resin (C) and a polyalkyleneimine, and an amorphous resin (A).

FIELD OF THE INVENTION

The present invention relates to a binder resin composition for toner, atoner for developing electrostatic images containing the binder resincomposition for toner, and a method for producing the binder resincomposition for toner.

BACKGROUND OF THE INVENTION

In the field of electrophotography, it is desired to develop a toner fordeveloping electrostatic images (hereinafter may be simply referred toas “toner”) that can enhance picture quality and can satisfy speed-uptechnique with the development of electrophotographic systems. Forexample, for corresponding with speed-up machines, a toner is requiredto have an excellent low-temperature fusing property.

However, in producing a large amounts of prints using a toner has a goodlow-temperature fusing property, the toner may fuse and/or firmly stickto a developing roll of an electrophotographic system to form streaks onthe printed images and there often occurs a problem in point of thedurability of the toner. Accordingly, a toner that satisfies bothlow-temperature fusing property and durability is desired.

For example, JP 2016-114829 A describes a toner for electrophotographywhich contains a crystalline composite resin that contains apolycondensed resin component prepared by polycondensation of an alcoholcomponent containing a specific aliphatic diol and a specific aliphaticcarboxylic acid, and a styrenic resin component; an amorphous compositeresin that contains a polycondensed resin component prepared bypolycondensation of an alcohol component and an aromatic dicarboxylicacid component, and a styrenic resin component; and a releasing agent,which satisfies a specific average degree of circularity, and which issuch that the content of particles having a particle size of 3 μm orless in the toner is 5.0% by number or less.

JP 2017-58591 A describes a toner which contains a binder resin andwhich is surface-modified with a polymer amine and is furthersurface-modified with a silicone-acrylic copolymer.

U.S. Pat. No. 5,032,484 describes a toner composition which containstoner particles having a specific average particle size and which hasthe ability to adhere to paper after thermal fusion, and in which thetoner particles contain a thermoplastic polymer having a specific glasstransition temperature, the polymer contains, as dispersed therein, aspecific amount of a colorant, a specific amount of at least onebenzenesulfonic acid-fatty acid ammonium salt, a specific amount of atleast one polydimethylsiloxane copolymer, and a specific amount of atleast one crystalline polyethyleneimine.

SUMMARY OF THE INVENTION

The present invention relates to a binder resin composition for toner,which contains a resin composition (C-P) prepared by condensing an acidgroup-having crystalline resin (C) and a polyalkyleneimine, and anamorphous resin (A).

DETAILED DESCRIPTION OF THE INVENTION

For improving the low-temperature fusing property of a toner, when thesoftening point and the glass transition temperature of the toner areplanned to be low, there occurs a negative effect that the storagestability of the toner lowers, and therefore, it is desired to develop atoner excellent in low-temperature fusing property, storage stabilityand durability.

Therefore, the present invention relates to a binder resin compositionfor toner excellent in low-temperature fusing property, storagestability and durability, a toner for developing electrostatic imagescontaining the binder resin composition for toner, and a method forproducing the binder resin composition for toner.

From a different viewpoint, even when the low-temperature fusingproperty of toner could be improved, the low-temperature fusing propertymay lower in long-term storage. Further, in such long-term storage, theelectrostatic property may also lower.

Therefore, the present invention relates to a binder resin compositionfor toner excellent in low-temperature fusing property, aging stabilityof low-temperature fusing property and charge stability in some aspect,a toner for developing electrostatic images containing the binder resincomposition for toner, and a method for producing the binder resincomposition for toner.

The present inventors have found that a binder resin composition fortoner containing a resin composition (C-P) prepared by condensing anacid group-having crystalline resin (C) and a polyalkyleneimine, and anamorphous resin (A) can solve the problems of low-temperature fusingproperty, storage stability and durability.

The present inventors have also found that, when the difference in aFedors solubility parameter (SP value) between the crystalline resin (C)and the amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or less, the problemsof low-temperature fusing property, aging stability of low-temperaturefusing property and charge stability can be solved.

Specifically, the present invention relates to the followingembodiments.

-   -   [1] A binder resin composition for toner, containing a resin        composition (C-P) prepared by condensing an acid group-having        crystalline resin (C) and a polyalkyleneimine, and an amorphous        resin (A).    -   [2] The binder resin composition for toner according to [1],        wherein the difference in a Fedors solubility parameter (SP        value) between the crystalline resin (C) and the amorphous        resin (A) is 1.3 (cal/cm³)^(1/2) or less.    -   [3] A toner for developing electrostatic images, containing the        binder resin composition of the above [1] or [2].    -   [4] A method for producing a binder resin composition for toner,        including:    -   Step 1: a step of condensing an acid group-having crystalline        resin (C) and a polyalkyleneimine to give a resin composition        (C-P), and    -   Step 2: a step of mixing the resin composition (C-P) and an        amorphous resin (A).    -   [5] The method for producing a binder resin composition for        toner according to [4], wherein the difference in a Fedors        solubility parameter (SP value) between the crystalline        resin (C) and the amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or        less.

According to the present invention, there can be provided a binder resincomposition for toner excellent in low-temperature fusing property,storage stability and durability, a toner for developing electrostaticimages containing the binder resin composition for toner, and a methodfor producing the binder resin composition for toner.

According to the above-mentioned embodiments [2] and [5], there can beprovided a binder resin composition for toner excellent inlow-temperature fusing property, aging stability of low-temperaturefusing property and charge property after storage, a toner fordeveloping electrostatic images containing the binder resin compositionfor toner, and a method for producing the binder resin composition fortoner.

[Binder Resin Composition for Toner]

The binder resin composition for toner of the first embodiment of thepresent invention (hereinafter may be simply referred to as “binderresin composition”) contains a resin composition (C-P) (hereinafter maybe simply referred to as “resin composition (C-P)”) prepared bycondensing an acid group-having crystalline resin (C) (hereinafter maybe simply referred to as “resin (C)”) and a polyalkyleneimine, and anamorphous resin (A) (hereinafter may be simply referred to as “resin(A)”).

According to the first embodiment of the present invention, there can beprovided a binder resin composition for toner excellent inlow-temperature fusing property, storage stability and durability, atoner for developing electrostatic images containing the binder resincomposition for toner, and a method for producing the binder resincomposition for toner.

The binder resin composition for toner of the second embodiment of thepresent invention (hereinafter may be simply referred to as “binderresin composition”) contains a resin composition (C-P) prepared bycondensing an acid group-having crystalline resin (C) and apolyalkyleneimine, and an amorphous resin (A), wherein the difference ina Fedors solubility parameter (hereinafter may be simply referred to as“SP value”) between the crystalline resin (C) and the amorphous resin(A) is 1.3 (cal/cm³)^(1/2) or less.

According to the second embodiment of the present invention, there canbe provided a binder resin composition for toner excellent inlow-temperature fusing property, aging stability of low-temperaturefusing property and charge property after storage, a toner fordeveloping electrostatic images containing the binder resin compositionfor toner, and a method for producing the binder resin composition fortoner.

The reason why the toner for developing electrostatic images containingthe binder resin composition for toner of the first embodiment of thepresent invention is excellent in low-temperature fusing property,storage stability and durability is, though not clear, considered to beas follows.

For improving the low-temperature fusing property of toner, use of acrystalline resin is general, and by finely dispersing a crystallineresin in an amorphous resin, the amorphous resin is plasticized duringfusing process to express a low-temperature fusing property. The tonerof the first embodiment of the present invention contains apolyalkyleneimine-derived moiety in the resin composition (C-P), inwhich the moiety forms an acid-base interaction with the acid groupmoiety in the acid group-having crystalline resin (C) and the acidgroup-having amorphous resin (A), and the resin composition (C-P) actsas a dispersant for the acid group-having resin (C), and accordingly, itis considered that the acid group-having resin (C) and the resincomposition (C-P) can be finely dispersed in the acid group-having resin(A) to better the low-temperature fusing property.

In general, an incompatible combination of a crystalline resin and anamorphous resin betters storage stability but worsens a low-temperaturefusing property. In the first embodiment of the present invention, theresin composition (C-P) and the acid group-having resin (C) finelydisperse in the acid group-having resin (A) owing to the above-mentionedacid-base interaction, and therefore it is considered that both thelow-temperature fusing property and the storage stability can bebettered.

In general, a crystalline resin has a lower glass transition temperaturethan an amorphous resin and, when existing in the surface of toner, itworsens durability. It is considered that the resin (C) is finelydispersed in the toner to prevent it from being exposed out on thesurface so as to retard durability degradation, and therefore thedurability can be thereby improved.

Though not clear, the reason why the toner of the second embodiment ofthe present invention is excellent in low-temperature fusing property,aging stability of low-temperature fusing property and charge propertyafter storage is considered to be as follows.

For improving the low-temperature fusing property of the toner of thesecond embodiment, use of a crystalline polyester is general, and whenthe SP value between the resin (C) and the resin (A) is smaller, theresins can be more readily plasticized during fusing to express a goodlow-temperature fusing property.

However, in general, the resin (C) often forms a large domain of theresin (C) during long-term storage to worsen a low-temperature fusingproperty, and the resin (C) may be exposed out on the surface of tonerto worsen charge property. The toner of the second embodiment contains apolyalkyleneimine in the resin (C) and forms acid-base interaction withthe carboxylic acid moiety in the resin so that the resin (C) can existstably in the resin (A). Namely, during long-term storage, it isconsidered that the resin (C) does not form a large domain and isprevented from being exposed out on the surface, and therefore the agingstability of low-temperature fusing property and charge property afterstorage can be thereby bettered.

The crystallinity of resin can be expressed by a crystallinity indexdefined by a ratio of the softening point to the endothermic maximumpeak temperature in differential scanning calorimetry (DSC), that is,“softening point/endothermic maximum peak temperature”. In general, whenthe crystallinity index is more than 1.4, the resin is amorphous, andwhen it is less than 0.6, the crystallinity is low and the amorphousmoiety in the resin is large. In the present invention, “crystallineresin” means a resin having a crystallinity index of 0.6 or more,preferably 0.7 or more, more preferably 0.9 or more, and is 1.4 or less,preferably 1.2 or less; and “amorphous resin” means a resin having acrystallinity index of more than 1.4 or less than 0.6.

The above-mentioned “endothermic maximum peak temperature” indicates apeak temperature for a maximum peak area among the endothermic peaksobserved under the condition of the measurement method described in thesection of Examples.

The crystallinity of resin can be controlled by the kind and the ratioof the raw material monomer, and the production conditions (for example,reaction temperature, reaction time, cooling speed).

The “solubility parameter value” or “SP value” in this description isone calculated according to the method proposed by Fedors et al., anddescribed in “POLYMER ENGINEERING AND SCIENCE, February, 1974, Vol. 14,No. 2, ROBERT F. FEDORS (pp. 147 to 154)”.

<Resin Composition (C-P)>

The resin composition (C-P) for use in the present invention is preparedby condensing an acid group-having crystalline resin (C) and apolyalkyleneimine. As described above, the resin composition (C-P)contains an unreacted resin (C) or a remaining polyalkyleneimine, aswell as a polyalkyleneimine-derived structure that the reaction productof a resin (C) and a polyalkyleneimine and a polyalkyleneimine-derivedside product have. With that, it is considered that thepolyalkyleneimine and the polyalkyleneimine-derived structure may formacid-base interaction with the acid group in the resin composition (C-P)and the resin (A). Also it is considered that, according to theinteraction, the resin (C) and the resin composition (C-P) are finelydispersed in the acid group-having amorphous resin (A) to improve thelow-temperature fusing property of the resultant toner.

(Acid Group-Having Crystalline Resin (C))

The acid group-having crystalline resin (C) for use in the presentinvention is preferably crystalline polyester-based resin such as acrystalline polyester and a crystalline composite resin having apolyester segment and a vinylic resin segment, and is more preferably acrystalline polyester.

The crystalline polyester is a polycondensate of an alcohol component(c-al) and a carboxylic acid component (c-ac).

In the present invention, “polyester-based resin” may contain apolyester modified in such a degree that would not substantially detractfrom the characteristics thereof. Examples of the modified polyesterinclude an urethane-modified polyester in which the polyester ismodified with an urethane bond, an epoxy-modified polyester in which thepolyester is modified with an epoxy bond, and a composite resin having apolyester component and an addition polymer-based resin component.“Polyester” means an unmodified “polyester”.

[Alcohol Component (c-Al)]

The alcohol component (c-al) preferably contains an α,ω-aliphatic diol.In the first embodiment, the carbon number of the α,ω-aliphatic, diol ispreferably 2 or more, more preferably 6 or more, even more preferably 11or more, and is preferably 16 or less, more preferably 14 or less, evenmore preferably 12 or less, from the viewpoint of more improvinglow-temperature fusing property, storage stability and durability.

In the second embodiment, the carbon number of the α,ω-aliphatic diolis, from the viewpoint of more improving low-temperature fusingproperty, aging stability of low-temperature fusing property and chargeproperty after storage, preferably 2 or more, more preferably 4 or more,even more preferably 6 or more, and is preferably 16 or less, morepreferably 10 or less, even more preferably 8 or less.

Examples of the α,ω-aliphatic diol include ethylene glycol,1,3-propanediol, 1,4-butane-diol, 1,5-pentanedial, 1,6-hexanediol,1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol,1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and1,14-tetradecanediol. Among these, in the first embodiment, from theviewpoint of easily obtaining a toner excellent in the balance ofvarious characteristics of low-temperature fusing property, storagestability and durability, ethylene glycol, 1,4-butanediol,1,6-hexanediol, 1,10-decanediol and 1,12-dodecanediol are preferred, andfrom the viewpoint of easily obtaining a toner more excellent indurability, 1,12-dodecanediol is preferred.

Among these, in the second embodiment, ethylene glycol, 1,4-butanediol,1,6-hexanediol, 1,10-decanediol and 1,12-dodecanediol are preferred,ethylene glycol, 1,4-butanediol and 1,6-hexanediol are more preferred;and 1,6-hexanediol is even more preferred, from the viewpoint of moreimproving low-temperature fusing property, aging stability oflow-temperature fusing property and charge property after storage.

The content of the α,ω-aliphatic diol in the alcohol component (c-al) ispreferably 80 mol % or more, more preferably 85 mol % or more, even morepreferably 90 mol % or more, further more preferably 95 mol % or more,and is 100 mol % or less, further more preferably 100 mol %.

The alcohol component (c-al) may contain any other alcohol componentdifferent from an α,ω-aliphatic diol. Examples of the other alcoholcomponent include an aliphatic diol except an α,ω-aliphatic diol, and anaromatic diol, an alicyclic diol and a trihydric or higher polyalcohol.

Examples of the aromatic alcohol include bisphenol A (C₁₋₄) alkyleneoxide adducts (average addition molar number, 1 to 16) such as2,2-bis(4-hydroxyphenyl)propane polyoxypropylene adduct, and2,2-bis(4-hydroxyphenyl)propane polyoxyethylene adduct.

Examples of the alicyclic diol include hydrogenated bisphenol A [same as2,2-bis(4-hydroxycyclohexyl)propane], and hydrogenated bisphenol A(C₂₋₄) alkylene oxide adducts (average addition molar number, 2 to 12).

Examples of the trihydric or higher polyalcohol include glycerin,pentaerythritol, trimethylolpropane, sorbitol, and sorbitan.

One alone or two or more kinds of these alcohol components may be usedeither singly or as combined. From the viewpoint of controlling themolecular weight and the softening point of the resultant polyesters,the alcohol component (c-al) may optionally contain a monohydricalcohol.

[Carboxylic Acid Component (c-ac)]

In the first embodiment, the carboxylic acid component that thecarboxylic acid component (c-ac) contains is preferably an α,ω-aliphaticdicarboxylic acid having 10 or more and 14 or less carbon atoms. Theα,ω-aliphatic dicarboxylic acid is preferably an α,ω-linear aliphaticdicarboxylic acid, from the viewpoint of easily obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, storage stability and durability.

The α,ω-aliphatic dicarboxylic acid having 10 or more and 14 or lesscarbon atoms is preferably sebacic acid, dodecanedioic acid, ortetradecanedioic acid, from the viewpoint of easily obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, storage stability and durability.

The content of the α,ω-aliphatic dicarboxylic acid having 10 or more and14 or less carbon atoms in the carboxylic acid component (c-ac) ispreferably 85 mol % or more, more preferably 90 mol % or more, even morepreferably 95 mol % or more, and is 100 mol % or less, preferably 100mol %.

The carboxylic acid component (c-ac) may contain any other aliphaticdicarboxylic acid than the α,ω-aliphatic dicarboxylic acid having 10 ormore and 14 or less carbon atoms, an aromatic dicarboxylic acid, analicyclic dicarboxylic acid, and a tribasic or higher polycarboxylicacid, within a range not detracting from the advantageous effects of thepresent invention.

Examples of the other aliphatic dicarboxylic acid than the α,ω-aliphaticdicarboxylic acid having 10 or more and 14 or less carbon atoms includeoxalic acid, malonic acid, fumaric acid, maleic acid, citraconic acid,itaconic acid, glutaconic acid, succinic acid, adipic acid, and azelaicacid.

Examples of the aromatic dicarboxylic acid, the alicyclic dicarboxylicacid and the tribasic or higher polycarboxylic acid are the same asthose to be exemplified hereinunder for the carboxylic acid componentthat the carboxylic acid component (a-ac) to be mentioned belowcontains.

In the second embodiment, the carboxylic acid component that thecarboxylic acid component (c-ac) contains is preferably an α,ω-aliphaticdicarboxylic acid having 4 or more and 14 or less carbon atoms, or anaromatic dicarboxylic acid, from the viewpoint of more improvinglow-temperature fusing property, aging stability of low-temperaturefusing property, and charge property after storage. The α,ω-aliphaticdicarboxylic acid is preferably an α,ω-linear aliphatic dicarboxylicacid.

The α,ω-aliphatic dicarboxylic acid having 4 or more and 14 or lesscarbon atoms is, preferably succinic acid, fumaric acid or sebacic acid,more preferably fumaric acid, from the viewpoint of easily obtaining atoner excellent in the balance of various characteristics oflow-temperature fusing property, aging stability of low-temperaturefusing property, and charge property after storage.

The content of the α,ω-aliphatic dicarboxylic acid having 4 or more and14 or less carbon atoms in the carboxylic acid component (c-ac) ispreferably 85 mol % or more, more preferably 90 mol % or more, even morepreferably 95 mol % or more, and is 100 mol % or less, preferably 100mol %.

The aromatic dicarboxylic acid is preferably phthalic acid, isophthalicacid or terephthalic acid, and more preferably terephthalic acid, fromthe viewpoint of easily obtaining a toner excellent in the balance ofvarious characteristics of low-temperature fusing property, agingstability of low-temperature fusing property, and charge property afterstorage.

The content of the aromatic dicarboxylic acid in the carboxylic acidcomponent (c-ac) is preferably 85 mol % or more, more preferably 90 mol% or more, even more preferably 95 mol % or more, and is 100 mol % orless, preferably 100 mol %.

The carboxylic acid component (c-ac) may contain any other aliphaticdicarboxylic acid than the α,ω-aliphatic dicarboxylic acid having 4 ormore and 14 or less carbon atoms, and an alicyclic dicarboxylic acid anda tribasic or higher polycarboxylic acid, within a range not detractingfrom the advantageous effects of the present invention.

Both in the first embodiment and in the second embodiment, one alone ortwo or more kinds of these carboxylic acid components may be used eithersingly or as combined. From the viewpoint of controlling the molecularweight and the softening point of the resultant polyester, thecarboxylic acid component (c-ac) may optionally contain a monocarboxylicacid.

In this description, the carboxylic acid component contains not only thecompound alone but also an anhydride to decompose during reaction toform an acid, and an alkyl ester of each carboxylic acid (in which thealkyl group has 1 or more and 3 or less carbon atoms). Also in thisdescription, in the case where the exemplified carboxylic acid componentis described merely as the name of a carboxylic acid (free acid)(excepting in the description of Examples), the description thereofincludes also an acid anhydride and an alkyl ester having 1 or more and3 or less carbon atoms of the carboxylic acid. Specifically, a meredescription of “trimellitic acid” includes a description of “trimelliticacid, trimellitic anhydride (same as “anhydrous trimellitic acid”), andan alkyl ester having 1 or more and 3 or less carbon atoms oftrimellitic acid”.

The equivalent ratio of the carboxy group (COOH group) of the carboxylicacid component (c-ac) to the hydroxy group (OH group) of the alcoholcomponent (c-al) [COOH group/OH group] is preferably 0.7 or more, morepreferably 0.8 or more, and is preferably 1.3 or less, more preferably1.2 or less.

The content of the crystalline polyester-based resin in the resin (C) ispreferably 70% by mass or more, more preferably 80% by mass or more,even more preferably 90% by mass or more, and is 100% by mass or less,preferably 100% by mass.

The content of the crystalline polyester in the resin (C) is preferably70% by mass or more, more preferably 80% by mass or more, even morepreferably 90% by mass or more, and is 100% by mass or less, preferably100% by mass, from the viewpoint of easily obtaining a toner excellentin the balance of various characteristics of low-temperature fusingproperty, storage stability, and durability, or from the viewpoint ofmore improving aging stability of low-temperature fusing property andcharge property after storage.

The softening point of the resin (C) is preferably 60° C. or higher,more preferably 70° C. or higher, even more preferably 75° C. or higher,from the viewpoint of more improving the storage stability and thedurability of toner, or from the viewpoint of more improving the agingstability of low-temperature fusing property and the charge propertyafter storage thereof, and is preferably 150° C. or lower, morepreferably 120° C. or lower, even more preferably 100° C. or lower, fromthe viewpoint of more improving the low-temperature fusing property.

The melting point of the resin (C) is preferably 50° C. or higher, morepreferably 60° C. or higher, even more preferably 65° C. or higher, fromthe viewpoint of more improving the storage stability and the durabilityof toner, or from the viewpoint of more improving the aging stability oflow-temperature fusing property and the charge property after storagethereof, and is preferably 130° C. or lower, more preferably 100° C. orlower, even more preferably 95° C. or lower, from the viewpoint of moreimproving the low-temperature fusing property of toner.

The acid value of the resin (C) is preferably 2 mgKOH/g or more, morepreferably 5 mgKOH/g or more, even more preferably 10 mgKOH/g or more,and is preferably 40 mgKOH/g or less, more preferably 30 mgKOH/g orless, even more preferably 20 mgKOH/g or less, from the viewpoint ofimproving reactivity with a polyalkyleneimine, and from the viewpoint ofeasily obtaining a toner excellent in the balance of variouscharacteristics of low-temperature fusing property, storage stabilityand durability, or from the viewpoint of easily obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, aging stability of low-temperature fusing property, andcharge property after storage.

In the second embodiment, the SP value of the resin (C) is preferably9.5 (cal/cm³)^(1/2) or more, more preferably 9.8 (cal/cm³)^(1/2) ormore, even more preferably 10.0 (cal/cm³)^(1/2) or more, and ispreferably 12.5 (cal/cm³)^(1/2) or less, more preferably 12.3(cal/cm³)^(1/2) or less, even more preferably 12.1 (cal/cm³)^(1/2) orless, and further more preferably 11.9 (cal/cm³)^(1/2) or less, from theviewpoint of more improving low-temperature fusing property, agingstability of low-temperature fusing property, and charge property afterstorage.

The softening point, the melting point and the acid value of the resin(C) can be appropriately controlled by the kind and the ratio of the rawmaterial monomer, and the production conditions such as the reactiontemperature, the reaction time, and the cooling speed. The values can bedetermined according to the methods described in the section of Examplesgiven hereinunder. In the case where two or more kinds of resins (C) areused as combined, preferably, the values of the softening point, themelting point and the acid value of the mixture of the resins each fallwithin the above-mentioned range.

In the case where the resin (C) is a crystalline polyester, thecrystalline polyester can be prepared, for example, by polycondensingthe alcohol component (c-al) and the carboxylic acid component (c-ac).

As needed, the polycondensation of the alcohol component (c-al) and thecarboxylic acid component (c-ac) can be carried out in the presence ofany other raw material component (e), an esterification catalyst, anesterification promoter and a polymerization inhibitor to be mentionedbelow.

The polycondensation can be carried out in an inert gas atmosphere suchas nitrogen.

Examples of the esterification catalyst include tin catalysts andtitanium catalysts. Examples of tin catalysts include dibutyltin oxide,and tin(II) di-(2-ethylhexanoate). From the viewpoint of reactivity,molecular weight control and control of resin properties, a tin(II)compound not having an Sn—C bond such as tin(II) di-(2-ethylhexanoate)is preferred. Examples of titanium catalysts include titanium compoundssuch as titanium diisopropylate bistriethanolaminate.

In the case of using an esterification catalyst, the blending amount ofthe esterification catalyst is preferably 0.01 parts by mass or more,more preferably 0.1 parts by mass or more, and is preferably 1.5 partsby mass or less, more preferably 1 part by mass or less, relative to 100parts by mass of the total amount of the raw material monomers for theresin (C) to be subjected to polycondensation reaction, for example, inthe case of using an alcohol component (c-al) and a carboxylic acidcomponent (c-ac) alone as the raw material monomers, relative to 100parts by mass of the total of the alcohol component (c-al) and thecarboxylic acid component (c-ac).

Examples of the esterification promoter include pyrogallol compounds.Pyrogallol compounds have a benzene ring in which three adjacenthydrogen atoms each are substituted with a hydroxy group, and examplesthereof include pyrogallol, gallic acid, gallic acid esters,benzophenone derivatives such as 2,3,4-trihydroxybenzophenone and2,2′,3,4-tetrahydroxybenzophenone; and catechin derivatives such asepigallocatechin, and epigallocatechin gallate. Among these, gallic aidis preferred.

In the case of using an esterification promoter, the blending amount ofthe esterification promoter is preferably 0.001 parts by mass or more,more preferably 0.005 parts by mass or more, even more preferably 0.01parts by mass or more, and is preferably 1 part by mass or less, morepreferably 0.4 parts by mass or less, even more preferably 0.2 parts bymass or less, relative to 100 parts by mass of the total amount of theraw material monomers for the resin (C) to be subjected topolycondensation reaction, for example, in the case of using an alcoholcomponent (c-al) and a carboxylic acid component (c-ac) alone as the rawmaterial monomers, relative to 100 parts by mass of the total of thealcohol component (c-al) and the carboxylic acid component (c-ac), fromthe viewpoint of reactivity.

Examples of the polymerization inhibitor include radical polymerizationinhibitors such as 4-tert-butylcatechol.

In the case of using a polymerization inhibitor, the blending amount ofthe polymerization inhibitor is, for example, in the case of using analcohol component (c-al) and a carboxylic acid component (c-ac) alone asthe raw material monomers, preferably 0.001 parts by mass or more and ispreferably 0.5 parts by mass or less, relative to 100 parts by mass ofthe total of the alcohol component (c-al) and the carboxylic acidcomponent (c-ac).

The temperature in polycondensation of the component (c-al) and thecarboxylic acid component (c-ac) is preferably 120° C. or higher, morepreferably 140° C. or higher, even more preferably 180° C. or higher,and is preferably 250° C. or lower, more preferably 240° C. or lower,even more preferably 230° C. or lower. Preferably, by reducing thepressure in the reaction system in a second half of polymerization, thereaction is promoted to control the resultant resin (C) so as to have adesired softening point.

(Polyalkyleneimine)

The polyalkyleneimine for use in the present invention is preferably apolyalkyleneimine in which the alkylene group has 1 or more and 5 orless carbon atoms. A polyalkyleneimine is a compound that reacts withthe acid group of the resin (C) through condensation so as to be takenin the molecular skeleton of the resin (C), and an unreacted remainingpolyalkyleneimine and a polyalkyleneimine-derived side products may alsobe contained in the resin composition (C-P).

The polyalkyleneimine in which the alkylene group has 1 or more and 5 orless carbon atoms is preferably a polyalkyleneimine in which thealkylene group has 2 or more and 4 or less carbon atoms, more preferablya polyethyleneimine or a polypropyleneimine, and even more preferably apolyethyleneimine. One alone or two or more kinds of thesepolyalkyleneimines can be used either singly or as combined.

The proportion of the polyalkyleneimine is preferably 0.05% by mass ormore, more preferably 0.1% by mass or more, and is preferably 1% by massor less, more preferably 0.5% by mass or less, relative to the totalamount of the resin composition (C-P) and the amorphous resin (A) to bementioned below, from the viewpoint of obtaining a toner excellent inthe balance of various characteristics of low-temperature fusingproperty, storage stability, and durability, or from the viewpoint ofobtaining a toner excellent in the balance of various characteristics ofaging stability of low-temperature fusing property, and charge propertyafter storage.

The proportion of the polyalkyleneimine also contains the contents ofunreacted remaining polyalkyleneimine and the polyalkyleneimine-derivedside products contained in the resin composition (C-P) as mentionedabove, in addition to the polyalkyleneimine taken in the molecularskeleton of the resin (C) as a result of condensation with the acidgroup of the resin (C). Accordingly, the proportion of thepolyalkyleneimine can also be calculated as the blending amount of thepolyalkyleneimine used in condensation.

The number-average molecular weight of the polyalkyleneimine ispreferably 150 or more, more preferably 500 or more, even morepreferably 800 or more, further more preferably 1,000 or more, and ispreferably 10,000 or less, more preferably 5,000 or less, even morepreferably 4,000 or less, further more preferably 3,000 or less, furthermore preferably 2,000 or less, from the viewpoint of obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, storage stability, and durability.

The number-average molecular weight of the polyalkyleneimine ispreferably 150 or more, more preferably 200 or more, and is preferably5,000 or less, more preferably 3,000 or less, even more preferably 2,000or less, further more preferably 1,000 or less, further more preferably500 or less, from the viewpoint of obtaining a toner excellent in thebalance of various characteristics of aging stability of low-temperaturefusing property, and charge property after storage.

The weight-average molecular weight of the polyalkyleneimine ispreferably 500 or more, more preferably 1,000 or more, even morepreferably 1,200 or more, further more preferably 1,800 or more, and ispreferably 10,000 or less, more preferably 8,000 or less, even morepreferably 4,000 or less, further more preferably 3,000 or less, fromthe viewpoint of obtaining a toner excellent in the balance of variouscharacteristics of low-temperature fusing property, storage stability,and durability.

The value of the molecular weight can be determined according to themethod described in the section of Examples.

The resin composition (C-P) for use in the present invention is preparedby condensing an acid group-having crystalline resin (C) and apolyalkyleneimine, as described above.

The production method for the resin composition (C-P) is the same as thestep 1 for the production method for a binder resin composition fortoner to be described hereinunder, and its description is omitted here.

<Amorphous Resin (A)>

The amorphous resin (A) for use in the present invention is preferablyone or more selected from the group consisting of an amorphouspolyester-based resin such as an amorphous polyester and an amorphouscomposite resin having a polyester segment and a vinylic resin segment,and a styrene-acrylic resin, and is, from the viewpoint of moreimproving the storage stability and the durability of toner, morepreferably an amorphous polyester-based resin, even more preferably anamorphous polyester.

The amorphous polyester is a polycondensate of an alcohol component(a-al) and a carboxylic acid component (a-ac).

[Alcohol Component (a-al)]

The alcohol component (a-al) is preferably one containing one or moreselected from the group consisting of a bisphenol A alkyleneoxide adduct(hereinafter also referred to as “BPA-AO”) and an aliphatic diol having2 or more and 6 or less carbon atoms, more preferably containing BPA-AO,from the viewpoint of obtaining a toner excellent in the balance ofvarious characteristics of low-temperature fusing property, storagestability, and durability.

BPA-AO is preferably BPA-AO represented by the following general formula(I):

In the general formula (I), OR¹¹ and R¹²O each independently representan alkyleneoxy group having 1 or more and 4 or less carbon atoms,preferably an ethyleneoxy group or a propyleneoxy group.

x and y each are an average addition molar number of alkyleneoxide, andare independently a positive number. From the viewpoint of obtaining atoner excellent in the balance of various characteristics oflow-temperature fusing property, storage stability, and durability, theaverage value of the sum of x and y is preferably 1 or more, morepreferably 1.5 or more, and is preferably 16 or less, more preferably 8or less, even more preferably 4 or less.

BPA-AO represented by the general formula (I) is preferably a bisphenolA propylene oxide adduct (hereinafter also referred to as “BPA-PO”), ora bisphenol A ethylene oxide adduct (hereinafter also referred to as“BPA-EO”), more preferably BPA-PO.

One alone or two or more kinds of BPA-AO represented by the generalformula (I) may be used either singly or as combined, and combined useof BPA-EO and BPA-PO is preferred, from the viewpoint of more improvingthe storage stability and durability of toner.

In the case where the alcohol component (a-al) contains BPA-AO, thecontent of BPA-AO in the alcohol component (a-al) is preferably 80 mol %or more, more preferably 90 mol % or more, even more preferably 95 mol %or more, further more preferably 98 mol % or more, and is 100 mol % orless, further more preferably 100 mol %.

Examples of the aliphatic diol having 2 or more and 6 or less carbonatoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol,1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol,neopentyl glycol, 1,4-butenediol, 1,2-pentanediol, 1,4-pentanediol,2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,5-hexanediol,2,5-hexanediol, 1,6-hexanediol, and 3,3-dimethyl-1,2-butanediol. Amongthese, one or more selected from the group consisting of 1,2-propanedioland 1,4-butanediol is preferred, from the viewpoint of obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, storage stability, and durability, and 1,2-propanediolis more preferred from the viewpoint of more improving thelow-temperature fusing property of toner. Also, a combination of1,2-propanediol and 1,4-butanediol is more preferred, from the viewpointof more improving storage stability and durability of toner.

In the case where the alcohol component (a-al) contains an aliphaticdiol having 2 or more and 6 or less carbon atoms, preferably, thecomponent contains an aliphatic diol having 3 or more and 6 or lesscarbon atoms and having a hydroxy group bonding to the secondary carbonatom thereof.

Examples of the aliphatic diol having 3 or more and 6 or less carbonatoms and having a hydroxy group bonding to the secondary carbon atomthereof include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol,2,3-butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol,1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, and3,3-dimethyl-1,2-butanediol, and the aliphatic diol is preferably one ormore selected from 1,2-propanediol and 2,3-butanediol, more preferably1,2-propanediol.

In the case where the alcohol component (a-al) contains an aliphaticdiol having 3 or more and 6 or less carbon atoms and having a hydroxygroup bonding to the secondary carbon atom thereof, as the aliphaticdiol having 2 or more and 6 or less carbon atoms, the content of thealiphatic diol having 3 or more and 6 or less carbon atoms and having ahydroxy group bonding to the secondary carbon atom thereof, ispreferably 50 mol % or more, more preferably 60 mol % or more, and evenmore preferably 70 mol % or more, and is preferably 100 mol % or less,in the aliphatic diol having 2 or more and 6 or less carbon atoms, fromthe viewpoint of obtaining a toner excellent in the balance of variouscharacteristics of low-temperature fusing property, storage stability,and durability.

From the viewpoint of more improving the low-temperature fusing propertyof toner, the content of the aliphatic diol having 3 or more and 6 orless carbon atoms and having a hydroxy group bonding to the secondarycarbon atom thereof is, in the aliphatic diol having 2 or more and 6 orless carbon atoms, preferably 80 mol % or more, more preferably 90 mol %or more, even more preferably 100 mol %.

Also, the content of the aliphatic diol having 3 or more and 6 or lesscarbon atoms and having a hydroxy group bonding to the secondary carbonatom thereof is preferably 95 mol % or less, more preferably 90 mol % orless even more preferably 80 mol % or less, in the aliphatic diol having2 or more and 6 or less carbon atoms, from the viewpoint of moreimproving the storage stability and durability of toner.

The alcohol component (a-al) may contain any other alcohol componentdifferent from BPA-AO and the aliphatic diol having 2 or more and 6 orless carbon atoms. Examples of the other alcohol component include anyother aliphatic diol than an aliphatic diol having 2 or more and 6 orless carbon atoms, any other aromatic diol than BPA-AO, an alicyclicdiol, and a trihydric or higher polyalcohol.

Examples of the other aromatic alcohol than BPA-AO include a2,2-bis(4-hydroxyphenyl)propane polyoxypropylene adduct.

Examples of the other aliphatic diol than an aliphatic diol having 2 ormore and 6 or less carbon atoms include 1,7-heptanediol, 1,8-octanediol,1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol,1,13-tridecanediol, and 1,14-tetradecanediol.

Examples of the alicyclic diol include hydrogenated bisphenol A, andhydrogenated bisphenol A (C₂₋₄) alkylene oxide adducts (average additionmolar number, 2 to 12).

Examples of the trihydric or higher polyalcohol include glycerin,pentaerythritol, trimethylolpropane, sorbitol, and sorbitan.

One alone or two or more kinds of these alcohol components may be usedeither singly or as combined. From the viewpoint of controlling themolecular weight and the softening point of the resultant polyesters,the alcohol component (a-al) may optionally contain a monohydricalcohol.

[Carboxylic Acid Component (a-ac)]

Examples of the carboxylic acid component that the carboxylic acidcomponent (a-ac contains include dicarboxylic acids, tribasic or higherpolycarboxylic acids, and derivatives such as anhydrides and (C₁₋₃)alkyl esters thereof.

The dicarboxylic acid includes aromatic dicarboxylic acids, aliphaticdicarboxylic acids, and alicyclic dicarboxylic acids, and at least oneselected from the group consisting of aromatic dicarboxylic acids andaliphatic dicarboxylic acids is preferred.

The carbon number of the dicarboxylic acid is preferably 2 or more, morepreferably 3 or more, and is preferably 30 or less, more preferably 20or less.

The aromatic dicarboxylic acid includes phthalic acid, isophthalic acid,and terephthalic acid; and isophthalic acid and terephthalic acid arepreferred, and terephthalic acid is more preferred.

The aliphatic dicarboxylic acid includes oxalic acid, malonic acid,maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconicacid, succinic acid, adipic acid, sebacic acid, 1,5-pentanedioic acid,1,12-dodecanedioic acid, azelaic acid, and succinic acid substitutedwith an alkyl group having 1 or more and 20 or less carbon atoms or analkenyl group having 2 or more and 20 or less carbon atoms (hereinafteralso referred to as “alkenylsuccinic acid”); and at least one selectedfrom the group consisting of fumaric acid, and succinic acid substitutedwith an alkyl group having 1 or more and 20 or less carbon atoms or analkenyl group having 2 or more and 20 or less carbon atoms is preferred,and a mixture of two or more selected from the group consisting offumaric acid, and succinic acid substituted with an alkyl group having 1or more and 20 or less carbon atoms or an alkenyl group having 2 or moreand 20 or less carbon atoms is more preferred.

The carbon number of the alkyl group or the alkenyl group that thealkenylsuccinic acid has is preferably 8 or more, more preferably 9 ormore, and is preferably 16 or less, more preferably 14 or less. Thealkyl group or the alkenyl group may be linear or branched. Preferredexamples of the alkenylsuccinic acid include octenylsuccinic acid,nonenylsuccinic acid, decenylsuccinic acid, undecenylsuccinic acid,dodecylsuccinic acid, dodecenylsuccinic acid, tridecenylsuccinic acid,tetradecenylsuccinic acid, and tetrapropenylsuccinic acid.

The carboxylic acid component (a-ac) preferably contains an aromaticdicarboxylic acid among the above-mentioned dicarboxylic acids, and morepreferably contains terephthalic acid.

The content of the aromatic dicarboxylic acid is preferably 50 mol % ormore in the carboxylic acid component (a-ac), more preferably 60 mol %or more, even more preferably 65 mol % or more, further more preferably70 mol % or more, and is 100 mol % or less, preferably 98 mol % or less,more preferably 95 mol % or less, even more preferably 90 mol % or less,further more preferably 85 mol % or less, from the viewpoint ofobtaining a toner excellent in the balance of various characteristics oflow-temperature fusing property, storage stability, and durability.

In the case where the carboxylic acid component (a-ac) contains analkenylsuccinic acid, the content of the alkenylsuccinic acid is,preferably 3 mol % or more, more preferably 5 mol % or more, even morepreferably 10 mol % or more, and is preferably 30 mol % or less, morepreferably 20 mol % or less, even more preferably 15 mol % or less, inthe carboxylic acid component (a-ac).

Examples of the tribasic or higher polycarboxylic acid include1,2,4-benzenetricarboxylic acid (trimellitic acid),2,5,7-naphthalenetricarboxylic acid, and pyromellitic acid. Among these,trimellitic acid is preferred.

In the case where the carboxylic acid component (a-ac) contains atribasic or higher polycarboxylic acid, the content of the tribasic orhigher polycarboxylic acid in the carboxylic acid component (a-ac) ispreferably 3 mol % or more, more preferably 5 mol % or more, even morepreferably 10 mol % or more, and is preferably 50 mol % or less, morepreferably 40 mol % or less, even more preferably 30 mol % or less.

One alone or two or more kinds of these carboxylic acid components maybe used either singly or as combined. From the viewpoint of controllingthe molecular weight and the softening point of the resultant polyester,the carboxylic acid component (a-ac) may optionally contain amonocarboxylic acid.

The equivalent ratio of the carboxy group (COOH group) of the carboxylicacid component (a-ac) to the hydroxy group (OH group) of the alcoholcomponent (a-al) [COOH group/OH group] is preferably 0.7 or more, morepreferably 0.8 or more, and is preferably 1.3 or less, more preferably1.2 or less, even more preferably 1.0 or less.

The content of the amorphous polyester-based resin in the resin (A) ispreferably 70% by mass or more, more preferably 80% by mass or more,even more preferably 90% by mass or more, and is 100% by mass or less,preferably 100% by mass.

The content of the amorphous polyester in the resin (A) is preferably70% by mass or more, more preferably 80% by mass or more, even morepreferably 90% by mass or more, and is 100% by mass or less, preferably100% by mass, from the viewpoint of easily obtaining a toner excellentin the balance of various characteristics of low-temperature fusingproperty, storage stability, and durability.

(Other Raw Material Component (e))

The raw material component for the resin (A) may use any other rawmaterial component (e)) (hereinafter also referred to as “component(e)”) along with the alcohol component (a-al) and the carboxylic acidcomponent (a-ac), within a range not detracting from the advantageouseffects of the present invention. The component (e) is not limited to acomponent that polycondensates along with the alcohol component (a-al)and/or the carboxylic acid component (a-ac), and may be any componentthat may be contained in the structure of the resultant resin.

The component (e) includes a monomer having different functional groupsin one molecule, for example, lactic acid having a carboxy group and ahydroxy group; and a polyester component previously formed throughpolycondensation of a polyol component and an acid component. In thecase where a polyester component previously formed throughpolycondensation of a polyol component and an acid component isincorporated, the component reacts with the above-mentioned alcoholcomponent and carboxylic acid component to be taken in the structure ofthe polycondensed resin.

Examples of the other component (e) than the above-mentioned rawmaterial components include raw material monomers for use formodification of an urethane-modified polyester or an epoxy-modifiedpolyester, and styrene compounds such as α-methylstyrene for use forforming an addition polymer resin component in a composite resin; andvinylic monomers such as a vinyl monomer having an alkyl group with 6 ormore and 22 or less carbon atoms such as 2-ethylhexyl (meth)acrylate,and bireactive monomers such as acrylic acid, methacrylic acid, andmaleic acid.

The component (e) is preferably a polyester component previously formedby polycondensation of a polyol component and an acid component amongthe above-mentioned raw material components, more preferably apolyethylene terephthalate (hereinafter also referred to as “PET”). AsPET, for example, usable are those produced through polycondensation ofethylene glycol and terephthalic acid or dimethyl terephthalateaccording to an ordinary method.

The intrinsic viscosity (hereinafter also referred to as “IV value”) ofPET is preferably 0.40 or more, more preferably 0.50 or more, even morepreferably 0.55 or more, and is preferably 1.0 or less, more preferably0.90 or less, even more preferably 0.80 or less, further more preferably0.75 or less, further more preferably 0.70 or less. The IV value can bean index of a molecular weight, from the viewpoint of improvingdurability of toner. The IV value of PET can be controlled bycontrolling the time for polycondensation.

The IV value can be determined, for example, as follows. A sample isdissolved in a mixed solvent of phenol/tetrachloroethane=60/40 (ratio bymass) to have a concentration of 0.4 g/dL therein, and the viscositythereof is measured with an Ubbelohde viscometer, and the IV value iscalculated according to the following expression.IV=(√{square root over ( )}(1+4kη)−1)/(2kC)

In the expression, k is a Huggins constant, C is a concentration (g/dL)of the sample solution, η=(t₁/t₀)−1, t₀ is a dropping time in second ofthe solvent alone, t₁ is a dropping time in second of the samplesolution, and k is 0.33.

PET is available as a commercial product, and the commercial productthereof includes “RAMAPET L1” (from Indorama Ventures, Corp., IV value:0.60), “RAMAPET N2G” (from Indorama Ventures Corp., IV value: 0.75),“TRN-MTJ” (from Teijin Limited, IV value: 0.53), and “TRN-RTJC” (fromTeijin Limited, IV value: 0.64).

In the case where the resin (A) contains a polyester componentpreviously formed through polycondensation of a polyol component and anacid component, the content of the polyester component each ispreferably 25 parts by mol or more, more preferably 40 parts by mol ormore, even more preferably 60 parts by mol or more, and is preferably100 parts by mol or less, more preferably 90 parts by mol or less, evenmore preferably 80 parts by mol or less, relative to 100 parts by mol ofthe total amount of the alcohol component (a-al).

In the case where PET is used as the component (e), the molar number ofPET is calculated as a molar number of the PET-derived ethylene glycolunit, and specifically, the value is calculated by dividing the amountof PET used (unit: g) by 192, in this description. The same shall applyto the molar number of the other polyester component than PET, and iscalculated as a molar number of the polyester component-derived alcoholunit.

The component (e) may use the raw material components for the resin (C)along with the alcohol component (c-al) and the carboxylic acidcomponent (c-ac), within a range not detracting from the advantageouseffects of the present invention.

The softening point of the resin (A) is preferably 80° C. or higher,more preferably 90° C. or higher, even more preferably 100° C. orhigher, further more preferably 110° C. or higher, from the viewpoint ofmore improving the storage stability and the durability of toner, orfrom the viewpoint of more improving the aging stability oflow-temperature fusing property, and the charge property after storagethereof, and is preferably 160° C. or lower, more preferably 150° C. orlower, even more preferably 140° C. or lower, further more preferably130° C. or lower, from the viewpoint of more improving thelow-temperature fusing property of toner.

The glass transition temperature of the resin (A) is preferably 40° C.or higher, more preferably 50° C. or higher, even more preferably 55° C.or higher, further more preferably 60° C. or higher, from the viewpointof more improving the storage stability and the durability of toner, orfrom the viewpoint of more improving the aging stability oflow-temperature fusing property, and the charge property after storagethereof, and is preferably 90° C. or lower, more preferably 80° C. orlower, even more preferably 75° C. or lower, from the viewpoint of moreimproving the low-temperature fusing property of toner.

The acid value of the resin (A) is preferably 2 mgKOH/g or more, morepreferably 5 mgKOH/g or more, even more preferably 10 mgKOH/g or more,and is preferably 40 mgKOH/g or less, more preferably 30 mgKOH/g orless, even more preferably 25 mgKOH/g or less, from the viewpoint of theinteraction between the polyalkyleneimine-derived structure and thecomponent in the resin composition (C-P), and from the viewpoint ofeasily obtaining a toner excellent in the balance of variouscharacteristics of low-temperature fusing property, storage stabilityand durability, or from the viewpoint of easily obtaining a tonerexcellent in the balance of various characteristics of low-temperaturefusing property, aging stability of low-temperature fusing property, andcharge property after storage.

In the second embodiment, the SP value of the resin (A) is preferably9.5 (cal/cm³)^(1/2) or more, more preferably 10.2 (cal/cm³)^(1/2) ormore, even more preferably 10.5 (cal/cm³)^(1/2) or more, and ispreferably 12.5 (cal/cm³)^(1/2) or less, more preferably 12.3(cal/cm³)^(1/2) or less, even more preferably 12.1 (cal/cm³)^(1/2) orless, further more preferably 11.9 (cal/cm³)^(1/2) or less, from theviewpoint of more improving low-temperature fusing property, agingstability of low-temperature fusing property, and charge property afterstorage.

The softening point, the glass transition temperature, and the acidvalue of the resin (A) can be appropriately controlled by the kind andthe ratio of the raw material monomer, and the production conditions ofthe reaction temperature, the reaction time and the cooling speed. Thesevalues can be determined according to the methods described in thesection of Examples given hereinunder. In the case where two or morekinds of resins (A) are used in combination, preferably, the softeningpoint, the glass transition temperature, and the acid value of themixture thereof each fall within the above-mentioned range.

In the case where the resin (A) is an amorphous polyester, for example,the amorphous polyester can be produced through polycondensation of thealcohol component (a-al) and the carboxylic acid component (a-ac).

As needed, the polycondensation of the alcohol component (a-al) and thecarboxylic acid component (a-ac) can be carried out in the presence ofthe component (e), an esterification catalyst, an esterificationpromoter and a polymerization inhibitor.

Preferred embodiments of the esterification catalyst, the esterificationpromoter and the polymerization inhibitor, and a preferred blendingamount thereof are the same as those described hereinabove for theproduction method for the resin (C).

The polycondensation can be carried out in an inert gas atmosphere suchas nitrogen.

The temperature in polycondensation of the alcohol component (a-al) andthe carboxylic acid component (a-ac) is preferably 140° C. or higher,more preferably 160° C. or higher, even more preferably 180° C. orhigher, and is preferably 250° C. or lower, more preferably 240° C. orlower, even more preferably 230° C. or lower.

Preferably, by reducing the pressure in the reaction system in a secondhalf of polymerization, the reaction is promoted to control theresultant resin (A) so as to have a desired softening point.

<Difference in SP Value>

In the second embodiment, the difference in a Fedors solubilityparameter (SP value) between the resin (C) and the resin (A) is 1.3(cal/cm³)^(1/2) or less from the viewpoint of obtaining a tonerexcellent in low-temperature fusing property, aging stability oflow-temperature fusing property, and charge property after storage.

The difference in the SP value is preferably 1.1 (cal/cm³)^(1/2) orless, more preferably 1.0 (cal/cm³)^(1/2) or less, even more preferably0.9 (cal/cm³)^(1/2) or less, further more preferably 0.7 (cal/cm³)^(1/2)or less, further more preferably 0.5 (cal/cm³)^(1/2) or less, and is 0(cal/cm³)^(1/2) or more.

The difference in the SP value means an absolute value of the differencebetween the SP value of the resin (C) and the SP value of the resin (A).

The ratio by mass of the amorphous resin (A) to the resin composition(C-P) [(A)/(C-P)] is preferably 65/35 or more, more preferably 75/25 ormore, even more preferably 85/15 or more, from the viewpoint ofobtaining a toner excellent in the balance of various characteristic oflow-temperature fusing property, storage stability, and durability, orfrom the viewpoint of easily obtaining a toner excellent in the balanceof various characteristics of low-temperature fusing property, agingstability of low-temperature fusing property, and charge property afterstorage, and is preferably 95/5 or less, more preferably 94/6 or less,even more preferably 92/8 or less, from the viewpoint of the agingstability of low-temperature fusing property and the durability oftoner.

The total content of the amorphous resin (A) and the resin composition(C-P) is preferably 80% by mass or more, more preferably 90% by mass ormore, even more preferably 95% by mass or more, and is 100% by mass orless, in 100% by mass of the binder resin composition. The total contentof the amorphous resin (A) and the resin composition (C-P) is morepreferably 100% by mass in 100% by mass of the binder resin composition.

[Production Method for Binder Resin Composition for Toner]

A production method for the binder resin composition for toner of thefirst embodiment of the present invention includes, from the viewpointof obtaining a binder resin composition for toner excellent inlow-temperature fusing property, storage stability, and durability, thefollowing steps:

-   -   Step 1: a step of condensing an acid group-having crystalline        resin (C) and a polyalkyleneimine to give a resin composition        (C-P), and    -   Step 2: a step of mixing the resin composition (C-P) and an        amorphous resin (A).

In the production method for the binder resin composition for toner ofthe second embodiment of the present invention, the difference in aFedors solubility parameter (SP value) between the crystalline resin (C)and the amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or less in theabove-mentioned production method, from the viewpoint of obtaining abinder resin composition for toner excellent in low-temperature fusingproperty, aging stability of low-temperature fusing property, and chargeproperty after storage.

The crystalline resin (C), the polyalkyleneimine, the resin composition(C-P) and the amorphous resin (A), and preferred embodiments thereof arethe same as those described hereinabove for the binder resin compositionfor toner, and the description of these is omitted here.

<Step 1>

The step 1 is a step of condensing an acid group-having crystallineresin (C) and a polyalkyleneimine to give a resin composition (C-P).

The temperature in condensation in the step 1 is preferably 50° C. orhigher, more preferably 100° C. or higher, even more preferably 130° C.or higher, and is preferably 235° C. or lower, more preferably 200° C.or lower, even more preferably 170° C. or lower.

The condensation time in the step 1 is appropriately changeable but ispreferably 10 minutes or more, more preferably 30 minutes or more, fromthe viewpoint of reactivity.

In the production method for the resin composition (C-P), an acidgroup-having crystalline resin (C) may be first formed and thencondensed with a polyalkyleneimine, or a polyalkyleneimine may be addedin the course of forming an acid group-having crystalline resin (C) andthen condensed with the resin.

The blending amount of the polyalkyleneimine for use for condensation inthe step 1 is preferably 0.05% by mass or more, more preferably 0.1% bymass or more, and is preferably 1% by mass or less, more preferably 0.5%by mass or less, relative to the total amount of the resultant resincomposition (C-P) and the amorphous resin (A), from the viewpoint ofobtaining a toner excellent in the balance of various characteristics oflow-temperature fusing property, storage stability, and durability.

<Step 2>

The step 2 is a step of mixing the resin composition (C-P) obtained inthe step 1 and an amorphous resin (A).

In the step 2, preferably, the two are mixed in such a manner that theratio by mass of the amorphous resin (A) to the resin composition (C-P)[(A)/(C-P)] could be 65/35 or more and 95/5 or less.

A more preferred range of the ratio by mass [(A)/(C-P)] is also the sameas the range described hereinabove for the binder resin composition fortoner.

A method of mixing the resin composition (C-P) and an amorphous resin(A) is not specifically limited, for example, they may be uniformlymixed using a Henschel mixer.

Prior to adding various additives that will be described hereinunder inthe column of a toner for developing electrostatic images, the additivesmay be previously mixed, or they may be mixed along with variousadditives.

In the case of simultaneously mixing them along with various additives,the same method as that to be described hereinunder for the productionmethod for a toner for developing electrostatic images can be employed.

Mixing in the step 2 can be carried out using a kneading machine such asa closed system kneader, a single or twin-screw extruder, or acontinuous open roll-type kneading machine, but a twin-screw extruder ora continuous open roll-type kneading machine is preferably used, fromthe viewpoint of improving dispersibility of a colorant and others to bementioned below in the binder resin, and a twin-screw extruder is morepreferred from the viewpoint of more improving the storage stability oftoner.

The temperature in mixing in the step 2 is preferably 80° C. or higher,more preferably 90° C. or higher, and is preferably 150° C. or lower,more preferably 130° C. or lower.

[Toner for Developing Electrostatic Images]

The toner for developing electrostatic images of the present inventioncontains the above-mentioned binder resin composition for toner of thepresent invention.

The binder resin composition for toner of the present invention ispreferably usable as a binder resin for the toner for developingelectrostatic images. The toner may contain any other binder resin thanthe binder resin composition of the present invention, for example, anyother resin such as a crystalline resin not having an acid group, withina range not detracting from the advantageous effects of the presentinvention.

The content of the binder resin composition of the present invention ispreferably 80% by mass or more, more preferably 90% by mass or more,even more preferably 95% by mass or more, and is 100% by mass or less,in the total amount, 100% by mass of the binder resin for the toner fordeveloping electrostatic images. The content of the binder resincomposition of the present invention is more preferably 100% by mass inthe total amount, 100% by mass of the binder resin for the toner fordeveloping electrostatic images.

(Colorant)

The toner may contain a colorant.

The colorant may be any of dyes and pigments usable as a colorant fortoner.

The dye includes azine dyes, anthraquinone dyes, perinone dyes, andrhodamine dyes, and examples thereof include C.I. Solvent Black 5, C.I.Solvent Black 7, Sprit Black SB, Toluidine Blue, C.I. Solvent Blue 11,C.I. Solvent Blue 12, C.I. Solvent Blue 35, C.I. Solvent Blue 59, C.I.Solvent Blue 74, 1-aminoanthraquinone, 2-aminoanthraquinone,hydroxyethylaminoanthraquinone, C.I. Solvent Violet 47, Solvent Orange60, Solvent Orange 78, Solvent Orange 90, Solvent Violet 29, Solvent Red135, Solvent Red 162, Solvent Red 179, and Rhodamine-B Base.

The pigment may be any of an inorganic pigment and an organic pigment.

The inorganic pigment includes carbon black and metal oxides.

The organic pigment includes azo pigments, diazo pigments,phthalocyanine pigments, quinacridone pigments, isoindolinone pigments,dioxazine pigments, perylene pigments, perinone pigments, thioindigopigments, anthraquinone pigments, and quinophthalone pigments. Theorganic pigment is preferably one or more products selected from thegroup consisting of C.I. Pigment Yellow, C.I. Pigment Red, C.I. PigmentOrange, C.I. Pigment Violet, C.I. Pigment Blue, and C.I. Pigment Green.

The hue of the colorant is not specifically limited, and any ofchromatic pigments of yellow, magenta, cyan, blue, red, orange and greenis usable. One alone or two or more kinds of these colorants may be usedeither singly or as combined.

The content of the colorant is preferably 1 part by mass or more, morepreferably 2 parts by mass or more, and is preferably 40 parts by massor less, more preferably 20 parts by mass or less, even more preferably10 parts by mass or less, relative to 100 parts by mass of the totalamount of the binder resin, from the viewpoint of improving the imagedensity of toner.

(Releasing Agent)

The toner may contain a releasing agent.

The releasing agent includes polypropylene wax, polyethylene wax,polypropylene-polyethylene copolymer wax; hydrocarbon waxes or theiroxides such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax,and Sasol wax; ester waxes such as carnauba wax, montan wax ordeoxidized wax thereof, and fatty acid ester wax; and fatty acid amides,fatty acids, higher alcohols, and fatty acid metal salts. These may beused either singly or in combination of two or more thereof.

The melting point of the releasing agent is preferably 60° C. or higher,more preferably 70° C. or higher, even more preferably 80° C. or higher,from the viewpoint of the transferability of toner, and is preferably150° C. or lower, more preferably 140° C. or lower, even more preferably130° C. or lower, from the viewpoint of low-temperature fusing property.

The content of the releasing agent is preferably 0.5 parts by mass ormore, more preferably 1 part by mass or more, even more preferably 1.5parts by mass or more, and is preferably 10 parts by mass or less, morepreferably 8 parts by mass or less, even more preferably 7 parts by massor less, relative to 100 parts by mass of the total amount of the binderresin, from the viewpoint of the low-temperature fusing property and theoffset resistance of toner.

(Charge Control Agent)

The toner may contain a charge control agent. The charge control agentmay be any of a positive charge control agent and a negative chargecontrol agent.

The positive charge control agent includes nigrosine dyes, for example,“Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “BONTRON(registered trademark) N-01”, “BONTRON (registered trademark) N-04”,“BONTRON (registered trademark) N-07”, “BONTRON (registered trademark)N-09”, and “BONTRON (registered trademark) N-11” (all from OrientChemical Industries Co., Ltd.); triphenylmethane dyes having a tertiaryamine as a side chain, and quaternary ammonium salt compounds, forexample, “BONTRON (registered trademark) P-51” (from Orient ChemicalIndustries Co., Ltd.), cetyltrimethylammonium bromide, and “COPY CHARGEPX VP435” (from Clariant Corporation); polyamine resins, for example,“AFP-B” (from Orient Chemical Industries Co., Ltd.); imidazolederivatives, for example, “PLZ-2001”, and “PLZ-8001” (all from ShikokuChemicals Corporation); and styrene-acrylic resins, for example“FCA-701PT” (from Fujikura Kasei Co., Ltd.).

The negative charge control agent includes metal-containing azo dyes,for example, “Barifast (registered trademark) Black 3804”, “BONTRON(registered trademark) S-31”, “BONTRON (registered trademark) S-32”,“BONTRON (registered trademark) S-34”, and “BONTRON (registeredtrademark) S-36” (all from Orient Chemical Industries, Co., Ltd.),“Aizenspiron Black TRH”, and “T-77” (from Hodogaya Chemical Co., Ltd.);metal compounds of benzylic acid compounds, for example “LR-147” and“LR-297” (all from Japan Carlit Co., Ltd.); metal compounds of salicylicacid compounds, for example, “BONTRON (registered trademark) E-81”,“BONTRON (registered trademark) E-84”, “BONTRON (registered trademark)E-88”, “BONTRON (registered trademark) E-304” (all from Orient ChemicalIndustries Co., Ltd.), and “TN-105” (from Hodogaya Chemical Co., Ltd.);copper phthalocyanine dyes: quaternary ammonium salts, for example,“COPY CHARGE PX VP434” (from Clariant Corporation), and nitroimidazolederivatives; and organic metal compounds. One alone or two or more ofthese charge control agents may be used either singly or as combined.

The content of the charge control agent is preferably 0.01 parts by massor more, more preferably 0.2 parts by mass or more, even more preferably0.5 parts by mass or more, relative to 100 parts by mass of the totalamount of the binder resin, from the viewpoint of suppressing tonerfogging, and is preferably 10 parts by mass or less, more preferably 5parts by mass or less, even more preferably 3 parts by mass or less,further more preferably 2 parts by mass or less, relative to 100 partsby mass of the total amount of the binder resin, from the viewpoint ofsuppressing toner fogging, from the viewpoint of low-temperature fusingproperty.

(Other Additives)

The toner may appropriately further contain additives such as a magneticpowder, a fluidity enhancer, a conductivity controlling agent, areinforcing filler such as a fibrous material, an antioxidant, ananti-aging agent, and a cleaning property enhancer as other additivesthereto.

In this description, toner before added with an external additive to bementioned below may also be referred to as “toner particles”. Theabove-mentioned colorant, releasing agent, charge control agent and theother additives are preferably added to the toner before mixed with anexternal additive, and the toner particles are preferably in the form ofa powder prepared by pulverizing and classifying a mixture containingthe other components than an external additive.

(External Additive)

The toner may further contain an external additive for improving thefluidity thereof. Examples of the external additive include inorganicfine particles of silica, alumina, titania, zirconia, tin oxide or zincoxide, and organic fine particles such as melamine resin fine particles,and polytetrafluoroethylene resin fine particles. The toner may containone alone or two or more kinds of these external additives. Among theseexternal additives, silica is preferred, and hydrophobic silicaprocessed for hydrophobization is more preferred.

Examples of the hydrophobization treatment agent for hydrophobizingsurfaces of silica particles include hexamethyldisilazane (HMDS),dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane(OTES), and methyltriethoxysilane. Among these, hexamethyldisilazane ispreferred.

In the case where toner particles are surface-treated with an externaladditive, the amount of the external additive is preferably 0.05 partsby mass or more, more preferably 0.08 parts by mass or more, even morepreferably 0.1 parts by mass or more, and is preferably 5 parts by massor less, more preferably 3 parts by mass or less, even more preferably 2parts by mass or less, relative to 100 parts by mass of toner particles,from the viewpoint of the charge property and the fluidity of toner.

The volume median particle diameter (D₅₀) of the toner is preferably 2μm or more, more preferably 3 μm or more, even more preferably 4 μm ormore, and is preferably 20 μm or less, more preferably 15 μm or less,even more preferably 10 μm or less. In this description, the volumemedian particle diameter (D₅₀) means a particle size at which acumulative volume frequency calculated on the basis of a volume fractionof the particles from a smaller particle size side thereof is 50%.

In the case where the toner is processed with the above-mentionedexternal additive, the preferred range of the volume median particlediameter (D₅₀) of the toner processed with the external additive is thesame as the volume median particle diameter (D₅₀) of the toner particlesbefore processed with the external additive. The volume median particlediameter (D₅₀) may be determined by the method described in the sectionof Examples below.

[Production Method for Toner for Developing Electrostatic Images]

The toner for developing electrostatic images may be a pulverized toneror an emulsified and aggregated toner, and may be a toner for developingelectrostatic images produced according to any conventionally-knownmethod, and, for example, the following production methods (1) to (3)may be employed for producing the toner.

-   -   (1) Method of melt-kneading a raw material mixture for toner        containing a binder resin composition and pulverizing the        resulting melt-kneaded material to thereby produce a toner        (hereinafter also referred to as “melt-kneading and pulverizing        method”);    -   (2) Method of aggregating and coalescing binder resin particles        formed of a binder resin composition in a raw material mixture        for toner which contains a dispersion prepared by dispersing a        binder resin composition in a water-soluble medium to give toner        particles to be a toner (hereinafter also referred to as        “aggregating and coalescing method”);    -   (3) Method of stirring a dispersion prepared by dispersing a        binder resin composition in a water-soluble medium and raw        materials for toner at a high speed to give toner particles to        be a toner.

From the viewpoint of enhancing the productivity of toner as well asfrom the viewpoint of improving the low-temperature fusing property, thestorage stability and the durability of toner, preferred is themelt-kneading and pulverizing method (1). In addition, a toner may alsobe produced by the aggregating and coalescing method (2).

In the case of producing the toner according to any of theaforementioned methods, the binder resin composition and the rawmaterials for the composition, as well as additives such as a colorant,a releasing agent and a charge control agent are the same as thosedescribed hereinabove for the binder resin composition for toner and thetoner for developing electrostatic images of the present invention, andthe preferred embodiments and the blending amount of the components (thesame amount as the above-mentioned content and the blending amount) arealso the same.

When the toner is produced by any of the aforementioned methods, theamount of the binder resin composition to be used is preferably 5% bymass or more, more preferably 30% by mass or more, even more preferably50% by mass or more, further more preferably 70% by mass or more,further more preferably 80% by mass or more, further more preferably 85%by mass or more, further more preferably 90% by mass or more, and is100% by mass or less, preferably 99% by mass or less, relative to 100parts by mass of the total content (in terms of the solid content) ofthe raw materials for the toner to be produced.

(1) Melt-Kneading and Pulverizing Method

The method (1) preferably includes the following steps T1-1 and T1-2.

-   -   Step T1-1: a step of melt-kneading a raw material mixture for        toner containing the binder resin composition of the present        invention.    -   Step T1-2: a step of pulverizing the melt-kneaded material        obtained in the step T1-1 and classifying the resulting        pulverized product.        <Step T1-1>

In the step T1-1, a raw material mixture for toner containing the binderresin composition of the present invention is melt-kneaded. In the stepT1-1, preferably, a raw material mixture for toner containing the binderresin composition of the present invention and further containingadditives such as a colorant, a releasing agent and a charge controlagent is melt-kneaded.

The melt-kneading may be conducted using a kneading machine such as aclosed-type kneader, a single- or twin-screw extruder, or a continuousopen roll kneader. From the viewpoint of improving the dispersibility ofa colorant and others in a binder resin, a twin-screw extruder or acontinuous open roll kneader is preferred, and from the viewpoint ofmore improving the storage stability of toner, a twin-screw extruder ismore preferred.

In a twin-screw extruder, the kneading zone is closed, in which,therefore, materials can be readily melted by the kneading heat to begenerated during kneading them.

The preset temperature of the twin-screw extruder is not influenced bythe melting properties of materials owing to the mechanism of theextruder, and in the extruder, materials can be melted and mixed at anintended temperature.

The preset temperature (barrel preset temperature) of the twin-screwextruder can be appropriately defined, and is, for example, preferably80° C. or higher, more preferably 90° C. or higher, and is preferably150° C. or lower, more preferably 130° C. or lower.

The rotary peripheral speed of the twin-screw extruder is preferably 0.1m/sec or more, more preferably 0.2 m/sec or more, even more preferably0.3 m/sec or more, and is preferably 1.0 m/sec or less, more preferably0.7 m/sec or less, even more preferably 0.5 m/sec or less, in the caseof a co-rotation twin-screw extruder, from the viewpoint of improvingthe dispersibility of additives such as a colorant, a releasing agentand a charge control agent in the toner, and from the viewpoint ofreducing the mechanical force in melt-kneading to suppress heatgeneration.

The open roll kneader is in the form of a kneader whose kneading sectionis not closed but opened such that heat of kneading generated upon thekneading can be readily released therefrom. In addition, the open rollkneader of a continuous type is preferably in the form of a kneaderequipped with at least two rolls. The open roll kneader of a continuoustype is a kneader equipped with two rolls that are different inperipheral speed from each other, i.e., a kneader equipped with a highspeed rotating-side roll having a high peripheral speed and a low speedrotating-side roll having a low peripheral speed. From the viewpoint ofimproving the dispersibility of additives such as a colorant, areleasing agent and a charge control agent in the toner, from theviewpoint of reducing the mechanical force in melt-kneading to suppressheat generation, and from the viewpoint of lowering the temperatureduring melt-kneading, preferably, the high-rotation side roll is aheating roll and the low-rotation side roll is a cooling roll.

The roll temperature can be controlled by the temperature of the heatingmedium that is allowed to pass through inside the rolls. The heatingtemperature inside the rolls is preferably 20° C. or higher, morepreferably 30° C. or higher and is preferably 150° C. or lower, morepreferably 140° C. or lower.

The rotating speed of rolls is preferably 50 r/min or more, morepreferably 100 r/min or more, even more preferably 150 r/min or more,and is preferably 350 r/min or less, more preferably 300 r/min or less,even more preferably 250 r/min or less, from the viewpoint of improvingthe dispersibility of additives such as a colorant, a releasing agentand a charge control agent in the toner, and from the viewpoint ofreducing the mechanical force in melt-kneading to suppress heatgeneration.

The peripheral speed of rolls is preferably 0.07 m/min or more, morepreferably 0.15 m/min or more, even more preferably 0.20 m/min or more,and is preferably 0.50 m/min or less, more preferably 0.45 m/min orless, even more preferably 0.40 m/min or less, from the viewpoint ofimproving the dispersibility of additives such as a colorant, areleasing agent and a charge control agent in the toner, and from theviewpoint of reducing the mechanical force in melt-kneading to suppressheat generation.

The structure, size, material and others of rolls are not particularlylimited, and the surface of rolls may also have any shape such as asmooth shape, a wavy shape or an irregular shape. However, preferably, aplurality of spiral grooves are engraved on the surface of rolls fromthe viewpoint of enhancing a shear force upon kneading and improvingdispersibility of additives such as a colorant, a releasing agent and acharge control agent in the toner, and from the viewpoint of reducingthe mechanical force in melt-kneading to suppress heat generation.

Preferably, the raw material mixture for toner that contains the binderresin composition to be fed to the kneader is previously uniformly mixedusing a Henschel mixer. Also, for example, the resin (A) and the resincomposition (C-P) that the binder resin composition contains may be fedto the step 1 as a previously mixed binder resin composition, or in thestep 1, the resin (A) and the resin composition (C-P) may be directlymixed and melt-kneaded to be a binder resin composition, and further maybe mixed and melt-kneaded with additives such as a colorant.

In the case where the resin (A) and the resin composition (C-P) aremixed and melt-kneaded in the step T1-1, as described above, the two arepreferably so mixed that the ratio by mass thereof [(A)/(C-P)] could be65/35 or more and 95/5 or less. A more preferred range of the ratio bymass [(A)/(C-P)] is also the same as the range mentioned hereinabove forthe binder resin composition for toner.

After the melt-kneaded material obtained in the step T1-1 is cooled soas to be pulverized, it is supplied to the subsequent step T1-2.

<Step T1-2>

In the step T1-2, the melt-kneaded material obtained in the step T1-1 ispulverized, and then classified.

The pulverization step may be conducted in multiple stages. For example,a resin kneaded material obtained by curing the melt-kneaded materialmay be coarsely pulverized into a size of 1 to 5 mm, and then the thusobtained coarsely pulverized product may be further finely pulverizedinto a desired particle size.

The pulverizer used in the pulverization step is not particularlylimited. Examples of the pulverizer suitably used for the coarsepulverization include a hammer mill, an atomizer, and a Rotoplex. Inaddition, examples of the pulverizer suitably used for the finepulverization include a jet mill such as a fluidized bed jet mill, andan impingement plate-type jet mill; and a rotating mechanical mill. Ofthese pulverizers, preferred is a jet mill from the viewpoint ofimproving pulverization efficiency.

Preferably, the pulverized product is further classified and controlledto have a desired particle size.

Examples of the classifier used for the classification step include arotor-type classifier, an airflow-type classifier, an inertiaclassifier, and a sieve-type classifier. An insufficiently pulverizedmatter that has been removed in the classification step may be againprocessed in the pulverization step, and if desired, the pulverizationstep and the classification step may be repeated.

<Surface Treatment with External Additive>

The toner particles obtained in the step T1-2 can be used as a toner fordeveloping electrostatic images as they are, but the toner particles maybe further processed with an external additive.

The processing method is not specifically limited. Preferably, the tonerparticles are processed with an external additive using a mixing machineequipped with a stirring tool such as a rotary impeller. Employableherein is a mixing method preferably using a high-speed mixing machinesuch as a Henschel mixer or a super mixer, more preferably a Henschelmixer.

The toner particles and the external additive are the same as thosementioned hereinabove for the toner for developing electrostatic imagesof the present invention, and preferred embodiments and the amount to beadded of the toner particles and the external additive are also thesame.

(2) Aggregating and Coalescing Method

The method (2) preferably includes the following steps T2-1, T2-2 andT2-3.

Step T2-1: a step of obtaining an aqueous dispersion of binder resinparticles containing the binder resin composition of the presentinvention.

-   -   Step T2-2: a step of aggregating the binder resin particles        obtained in the step T2-1 and optionally raw materials for toner        to give aggregated particles.    -   Step T2-3: a step of coalescing the aggregated particles        obtained in the step T2-2.        <Step T2-1>

The aqueous dispersion of binder resin particles containing the binderresin composition of the present invention (hereinafter also referred toas an “aqueous dispersion”) is preferably produced by the following stepT2-1a.

Step T2-1a: a step of adding an aqueous medium to an organic solventsolution containing the binder resin composition of the presentinvention to subject the solution to phase inversion emulsification,thereby giving an aqueous dispersion of binder resin particlescontaining the binder resin composition.

In this description, the aqueous dispersion may be any one that containsbinder resin compositions existing in a dispersed state in a solventcontaining an aqueous medium. Preferably, the aqueous medium existswithout being in a separate layer at 25° C. for 24 hours.

Also in this description, particles containing the binder resincomposition that are contained in the aqueous dispersion may be referredto as “binder resin particles”.

In the aqueous dispersion, any other organic solvent than an aqueousmedium can exist, and the content of the aqueous medium in the totalamount of the aqueous medium and the organic solvent is preferably 50%by mass or more, more preferably 70% by mass or more, even morepreferably 80% by mass or more, further more preferably 85% by mass ormore.

In the step of obtaining the aqueous dispersion containing the binderresin composition, a neutralizing agent and a surfactant may be mixedtherein, further when needed.

In the following, a phase inversion emulsification method is described.

Phase inversion emulsification may be conducted by adding an aqueousmedium to an organic solvent solution of the binder resin composition ofthe present invention. When adding an aqueous medium to an organicsolvent solution, a W/O phase is first formed, and then this issubjected to phase inversion into an O/W phase. Whether the phaseinversion takes place or not may be confirmed, for example, byobservation by naked eyes, or measurement of electrical conductivity.

In the phase inversion step, the particle size of binder resin particlesmay be controlled by controlling the adding velocity and the amount ofthe aqueous medium to be added, as described below.

The organic solvent solution containing the binder resin composition canbe produced according to a method of optionally mixing or kneading theresin binder composition and then dissolving or dispersing in an organicsolvent.

Also for example, the resin (A) and the resin composition (C-P) that thebinder resin composition contains may be previously mixed to give thebinder resin composition and the resultant composition may be dissolvedor dispersed in an organic solvent, or the resin (A) and the resincomposition (C-P) may be independently, or simultaneously orsuccessively, directly dissolved or dispersed in an organic solvent togive the binder resin composition, or the resin (A) is dissolved ordispersed in an organic solvent and the resin composition (C-P) isdissolved or dispersed in an organic solvent, and the resultant twoorganic solvents may be mixed to give the binder resin composition.

In the case where the resin (A) and the resin composition (C-P) aremixed to give the binder resin composition in the step T2-1a,preferably, the two are mixed in a ratio by mass [(A)/(C-P)] of 65/35 to95/5, as described above. A preferred range of the ratio by mass[(A)/(C-P)] is also the same as the range thereof described hereinabovefor the binder resin composition for toner.

When the mixture is stirred in this step, a common mixing and stirringdevice such as an anchor blade, or a high-speed stirring and mixingdevice such as Despa (from Asada Iron Works Co., Ltd.), T.K. Homomixer,T.K. Homodisper, and T.K. Robomix (all from Primix Corporation), Cleamix(from M Technique Corporation), and KD Mill (from KD InternationalCorporation) can be used.

(Organic Solvent)

From the viewpoint of the solubility of the resin to be used therein,the organic solvent preferably has a solubility parameter (SP value:refer to “Polymer Handbook, Third Edition”, published in 1989 by JohnWiley & Sons, Inc.) of 15.0 MPa^(1/2) or more, more preferably 16.0MPa^(1/2) or more and even more preferably 17.0 MPa^(1/2) or more, andalso preferably 26.0 MPa^(1/2) or less, more preferably 24.0 MPa^(1/2)or less and even more preferably 22.0 MPa^(1/2) or less.

Examples of the organic solvent include alcohol solvents such as ethanol(26.0), isopropanol (23.5) and isobutanol (21.5); ketone solvents suchas acetone (20.3), methyl ethyl ketone (19.0), methyl isobutyl ketone(17.2) and diethyl ketone (18.0); ether solvents such as dibutyl ether(16.5), tetrahydrofuran (18.6) and dioxane (20.5); and acetate solventssuch as ethyl acetate (18.6) and isopropyl acetate (17.4). Theparenthesized value on the right side of the name of each organicsolvent is an SP value thereof and the unit is MPa^(1/2). Among these,preferred is ketone solvent or acetate solvent, and one or more selectedfrom methyl ethyl ketone, ethyl acetate and isopropyl acetate arepreferred. Above all, ketone solvents are more preferred, and methylethyl ketone is even more preferred.

The ratio by mass of the organic solvent to the binder resin composition(organic solvent/binder resin composition) is preferably 0.1 or more,more preferably 0.2 or more and even more preferably 0.25 or more, andis also preferably 1 or less, more preferably 0.8 or less and even morepreferably 0.7 or less.

(Neutralizing Agent)

In the step T2-1a, it is preferable to add a neutralizing agent to thebinder resin composition from the viewpoint of improving the dispersionstability of the binder resin composition.

Examples of the neutralizing agent include hydroxides of alkali metalssuch as lithium hydroxide, sodium hydroxide and potassium hydroxide;ammonia; and organic base compounds such as trimethylamine, ethylamine,diethylamine, triethylamine, triethanolamine and tributylamine. Amongthese, sodium hydroxide is preferred.

The neutralization temperature is preferably 30° C. or higher, morepreferably 50° C. or higher, even more preferably 60° C. or higher, andis preferably 90° C. or lower, more preferably 85° C. or lower, evenmore preferably 80° C. or lower.

In the case where a neutralizing agent is used, the equivalent (mol %)of the neutralizing agent to be used, is preferably 10 mol % or more,more preferably 20 mol % or more and even more preferably 30 mol % ormore, and is also preferably 150 mol % or less, more preferably 100 mol% or less and even more preferably 80 mol % or less, on the basis of anacid group of the binder resin.

The equivalent (mol %) of the neutralizing agent to be used may bedetermined according to the following expression. In the case where theequivalent of the neutralizing agent used is 100 mol % or less, theequivalent of the neutralizing agent used has the same meaning as thatof a degree of neutralization of the resin with the neutralizing agent.Equivalent of neutralizing agent used (mol %)=[{mass (g) of neutralizingagent added/equivalent of neutralizing agent}/[{weight average acidvalue of resin to constitute binder resin particles (mgKOH/g)×mass (g)of resin to constitute binder resin particles (g)}/(56×1,000)]]×100(Aqueous Medium)

The aqueous medium preferably contains water as a main component.

Examples of components other than water include water-soluble organicsolvents, e.g., aliphatic alcohols having 1 or more and 5 or less carbonatoms, such as methanol, ethanol, isopropanol and butanol; dialkylketones containing an alkyl group having 1 or more and 3 or less carbonatoms, such as acetone and methyl ethyl ketone; and cyclic ethers suchas tetrahydrofuran. Among these, preferably used are alcohol-typeorganic solvents that do not dissolve polyester-based resins, such asmethanol, ethanol, isopropanol and butanol, from the viewpoint ofpreventing them from being mixed in toner.

From the viewpoint of improving dispersion stability of binder resinparticles, the content of water in the aqueous medium is preferably 80%by mass or more, more preferably 90% by mass or more and even morepreferably 95% by mass or more, and is also 100% by mass or less, andfurther more preferably 100% by mass. Water is preferably ion-exchangedwater or distilled water.

The temperature upon addition of the aqueous medium is preferably 15° C.or higher, more preferably 20° C. or higher and even more preferably 25°C. or higher, and is also preferably 80° C. or lower, more preferably75° C. or lower, from the viewpoint of improving dispersion stability ofbinder resin particles.

From the viewpoint of improving dispersion stability of binder resinparticles, the velocity of addition of the aqueous medium before phaseinversion emulsification is preferably 0.1 parts by mass/minute or more,more preferably 1 part by mass/minute or more and even more preferably 3parts by mass/minute or more, and is also preferably 50 parts bymass/minute or less, more preferably 20 parts by mass/minute or less andeven more preferably 10 parts by mass/minute or less, on the basis of100 parts by mass of the binder resin composition. The velocity ofaddition of the aqueous medium after phase inversion emulsification isnot particularly limited.

From the viewpoint of improving dispersion stability of binder resinparticles as well as from the viewpoint of obtaining uniform aggregatedparticles in the subsequent aggregation step, the amount of the aqueousmedium to be added is preferably 100 parts by mass or more, morepreferably 200 parts by mass or more and even more preferably 400 partsby mass or more, and is also preferably 900 parts by mass or less, morepreferably 800 parts by mass or less and even more preferably 700 partsby mass or less, on the basis of 100 parts by mass of the binder resincomposition.

(Surfactant)

In the step T2-1a, from the viewpoint of improving dispersion stabilityof the binder resin composition, preferably, a surfactant is added tothe binder resin composition.

The surfactant include a nonionic surfactant, an anionic surfactant anda cationic surfactant. Among these surfactants, preferred are one ormore selected from a nonionic surfactant and an anionic surfactant, andmore preferred is an anionic surfactant, from the viewpoint of improvingdispersion stability of binder resin particles.

The nonionic surfactant includes polyoxyethylene alkyl aryl ethers andpolyoxyethylene alkyl ethers; such as polyoxyethylene nonyl phenylether, polyoxyethylene oleyl ether and polyoxyethylene lauryl ether;polyoxyethylene fatty acid esters, such as polyethylene glycolmonolaurate, polyethylene glycol monostearate and polyethylene glycolmonooleate; and oxyethylene/oxypropylene block copolymers. Among these,polyoxyethylene alkyl ethers are preferred from the viewpoint ofimproving dispersion stability of binder resin particles.

The anionic surfactant includes alkyl benzenesulfonic acid salts such assodium alkylbenzenesulfonates; alkyl sulfuric acid salts such as sodiumalkylsulfates; and alkyl ether sulfates such as sodium alkyl ethersulfates. Among these, preferred are sodium alkylbenzenesulfonates andalkyl ether sulfates, more preferred are alkyl ether sulfates, even morepreferred are sodium alkyl ether sulfates, and further more preferredare sodium polyoxyethylene lauryl ether sulfate, from the viewpoint ofimproving dispersion stability of binder resin particles.

The cationic surfactant includes alkyltrimethylammonium chlorides, anddialkyldimethylammonium chlorides.

The surfactant may be mixed in an organic solvent solution and/or anaqueous dispersion containing the binder resin composition, beforeand/or after the above-mentioned phase inversion emulsification.

In the case where the surfactant is used, the amount of the surfactantto be added is preferably 0.5 parts by mass or more, more preferably 1part by mass or more, even more preferably 2 parts by mass or more, andis preferably 20 parts by mass or less, more preferably 15 parts by massor less, even more preferably 13 parts by mass or less, relative to 100parts by mass of the binder resin composition, from the viewpoint ofdispersion stability of binder resin particles.

(Removal of Organic Solvent)

After the phase inversion emulsification, if desired, the process mayinclude a step of removing the organic solvent from the dispersionobtained through the phase inversion emulsification.

The method for removing the organic solvent is not specifically limited,but distillation is preferred. For distillation, preferably, the systemis heated up to a temperature not lower than the boiling point of theorganic solvent. From the viewpoint of maintaining the dispersionstability of binder resin particles, reduced-pressure distillation ismore preferred. The organic solvent may remain in the aqueousdispersion, and the remaining amount thereof is preferably 1% by mass orless, more preferably 0.5% by mass or less, even more preferablysubstantially 0%, in the aqueous dispersion.

(Volume Median Particle Diameter (D₅₀) of Binder Resin Particles)

The volume median particle diameter (D₅₀) of the binder resin particlesin the aqueous dispersion is preferably 100 nm or more, more preferably150 nm or more and even more preferably 200 nm or more, and is alsopreferably 800 nm or less, more preferably 600 nm or less and even morepreferably 300 nm or less.

Here, the volume median particle diameter (D₅₀) means a particle size atwhich a cumulative volume frequency calculated on the basis of a volumefraction of the particles from a smaller particle size side thereof is50%, and may be determined by the method described in the section ofExamples below.

<Step T2-2>

The step T2-2 is a step of aggregating the binder resin particlesobtained in the step T2-1 to obtain aggregated particles.

In this step, an aggregating agent is preferably added to efficientlyconduct aggregation of the binder resin particles. In addition, in thestep T2-2, various additives such as a colorant, a charge control agent,a releasing agent, a magnetic powder, a conductivity controlling agent,a reinforcing filler such as a fibrous substance, and an antioxidant, ananti-aging agent and a cleaning property enhancer may be added.

(Aggregating Agent)

The aggregating agent for use herein includes organic aggregating agentssuch as cationic surfactants of quaternary salts and polyalkyleneimines;and inorganic aggregating agents such as inorganic metal salts andinorganic ammonium salts. Among these, preferred are inorganicaggregating agents, and more preferred are inorganic metal salts.

Examples of the inorganic metal salts include sodium sulfate, sodiumchloride, calcium chloride, calcium nitrate, barium chloride, magnesiumchloride, zinc chloride and aluminum chloride. Among these, preferred iscalcium chloride. Preferably, the valence of the center metal of theinorganic metal salts is divalent or higher.

The amount of the aggregating agent to be used is preferably 0.10 partsby mass or more, more preferably 0.15 parts by mass or more and evenmore preferably 0.20 parts by mass or more, and also is preferably 5parts by mass or less, more preferably 1 part by mass or less and evenmore preferably 0.5 parts by mass or less, on the basis of 100 parts bymass of the binder resin particles, from the viewpoint of wellcontrolling the aggregation of binder resin particles to obtainaggregated particles having a desired particle size. The aggregatingagent is preferably added in the form of an aqueous solution prepared bydissolving the aggregating agent in an aqueous medium.

The solid concentration in the system in the step T2-2 is preferably 5%by mass or more, more preferably 10% by mass or more and even morepreferably 15% by mass or more, and is also preferably 50% by mass orless, more preferably 40% by mass or less and even more preferably 30%by mass or less, from the viewpoint of allowing uniform aggregation.

The temperature in the system during addition of an aggregating agentthereto is preferably 0° C. or higher, more preferably 10° C. or higherand even more preferably 15° C. or higher, and is also preferably 60° C.or lower, more preferably 55° C. or lower and even more preferably 50°C. or lower, from the viewpoint of improving productivity of toner.

(Colorant)

In the step T2-2, the colorant may be added in the form of a colorantdispersion containing colorant particles.

The volume median particle diameter (D₅₀) of colorant particles ispreferably 50 nm or more, more preferably 80 nm or more and even morepreferably 100 nm or more, and is also preferably 500 nm or less, morepreferably 300 nm or less and even more preferably 150 nm or less, fromthe viewpoint of obtaining a toner capable of forming high-qualityimages.

(Releasing Agent)

In the step T2-2, the releasing agent may be added in the form of areleasing agent particle dispersion containing releasing agentparticles.

The volume median particle diameter (D₅₀) of releasing agent particlesis preferably 100 nm or more, more preferably 300 nm or more, and ispreferably 1,000 nm or less, more preferably 700 nm or less, from theviewpoint of durability.

(Charge Control Agent)

In the step T2-2, the charge control agent may be added in the form of acharge control agent dispersion containing a charge control agent.

The volume median particle diameter (D₅₀) of charge control agentparticles is preferably 100 nm or more, more preferably 300 nm or more,and is preferably 800 nm or less, more preferably 500 nm or less, fromthe viewpoint of low-temperature fusing property.

The volume median particle diameter (D₅₀) of the aggregated particlesobtained in the step T2-2 is preferably 2 μm or more, more preferably 3μm or more and even more preferably 4 μm or more, and is also preferably10 μm or less, more preferably 9 μm or less and even more preferably 8μm or less, from the viewpoint of low-temperature fusing property.

<Step T2-3>

The step T2-3 is a step of coalescing the aggregated particles obtainedin the step T2-2. In this step, the particles that are present asaggregated particles under such a condition that they are allowed toadhere to each other mainly by a physical force solely are coalesced andintegrated together to form coalesced particles.

In this step, the reaction system is preferably maintained at atemperature not lower than the glass transition temperature of the resin(A), from the viewpoint of improving the coalescing property of theaggregated particles.

From the viewpoint of improving the coalescing property of theaggregated particles and from the viewpoint of improving theproductivity of toner, the holding temperature in this step ispreferably not lower than a temperature higher by 5° C. than the glasstransition temperature of the resin (A), more preferably higher by 10°C. than the glass transition temperature of the resin (A), even morepreferably higher by 15° C. than the glass transition temperature of theresin (A), and is preferably not higher than a temperature higher by 50°C. than the glass transition temperature of the resin (A), morepreferably not higher by 30° C. than the glass transition temperature ofthe resin (A), even more preferably not higher by 20° C. than the glasstransition temperature of the resin (A).

Specifically, the holding temperature is preferably 70° C. or higher,more preferably 75° C. or higher, and is preferably 100° C. or lower,more preferably 90° C. or lower. The stirring speed is preferably suchthat the aggregated particles do not settle out at the speed.

In the case where an aggregation stopping agent is used, it ispreferably a surfactant, more preferably an anionic surfactant. Theanionic surfactant is preferably one or more selected from the groupconsisting of alkyl ether sulfate salts, alkyl sulfate salts, and linearalkylbenzenesulfonate salts, and alkyl ether sulfate salts are morepreferred.

<Post-Treatment Step>

The coalesced particles obtained in the aforementioned step are thenappropriately subjected to a solid-liquid separation step such asfiltration, a washing step and a drying step to thereby favorably givethe toner of the present invention.

In the washing step, preferably, the added surfactant is washed away,and preferably, the particles are washed with an aqueous solution of anonionic surfactant at a temperature not higher than the clouding pointof the surfactant. Also preferably, the washing is repeated pluraltimes.

In the drying step, a vibration-type fluidized drying method, a spraydrying method, a freeze drying method, or a flush jet method may beemployed. The water content in the toner after drying is preferably 1.5%by mass or less, more preferably 1.0% by mass or less, from theviewpoint of charge property.

<Surface Treatment with External Additive>

The toner particles obtained via the steps T2-1 to T2-3 can be used as atoner for developing electrostatic images as they are, but the tonerparticles may be further processed with an external additive.

The processing method is not specifically limited. Preferably, the tonerparticles are processed with an external additive using a mixing machineequipped with a stirring tool such as a rotary impeller. Employableherein is a mixing method preferably using a high-speed mixing machinesuch as a Henschel mixer or a super mixer, more preferably a Henschelmixer.

The toner particles and the external additive are the same as thosementioned hereinabove for the toner for developing electrostatic imagesof the present invention, and preferred embodiments and the amount to beadded of the toner particles and the external additive are also thesame.

The toner for developing electrostatic images of the present invention,and the toner for developing electrostatic images obtained according tothe production method of the present invention can be used as aone-component developing toner, or as a two-component developing tonermixed with a carrier, each in a one-component development system ortwo-component development system image forming device.

EXAMPLES

The properties of raw materials and others were measured and evaluatedaccording to the following methods.

[Number-Average Molecular Weight (Mn) and Weight-Average MolecularWeight (Mw) of Polyalkyleneimine]

Molecular weight distribution was determined according to gel permeationchromatography (GPC) mentioned below, and the number-average molecularweight and the weight-average molecular weight were calculated.

(1) Preparation of Sample Solution

A polyalkyleneimine was dissolved in a solution prepared by dissolving0.15 mol/L of Na₂SO₄ in an aqueous solution of 1% acetic acid so as tohave a concentration of 0.2 g/100 mL. Next, the solution was filteredthrough a fluororesin filter “FP-200” (from Sumitomo ElectricIndustries, Ltd.) having a pore size of 0.2 μm to remove insolublecomponents to give a sample solution.

(2) Molecular Weight Measurement

A measurement device and an analytical column mentioned below were used.As an eluent, a solution prepared by dissolving 0.15 mol/L of Na₂SO₄ inan aqueous solution of 1% acetic acid was let to run through the columnat a flow rate of 1 mL/min, and the column was stabilized in aconstant-temperature bath at 40° C. 100 μL of the sample solution wasintroduced into the column and measured. The molecular weight of thesample was calculated based on the calibration curve previouslyprepared. For the calibration curve, used were a few kinds of standardpullulan (P-5 (5.9×10³), P-50 (4.73×10⁴), P-200 (2.12×10⁵), P-800(7.08×10⁵) from Showa Denko K.K.) as standard samples. Measurementdevice: HLC-8320 GPC (from Tosoh Corporation) Analytical column:α+α-M+α-M (from Tosoh Corporation)

[Softening Point of Resin]

Using a flow tester “CFT-500D” (from Shimadzu Corporation), 1 g of asample was extruded through a nozzle having a die pore diameter of 1 mmand a length of 1 mm while heating the sample at a temperature rise rateof 6° C./min and applying a load of 1.96 MPa thereto by a plunger. Thesoftening point was determined as the temperature at which a half amountof the sample was flowed out when plotting a downward movement of theplunger of the flow tester relative to the temperature.

[Glass Transition Temperature of Resin]

Using a differential scanning calorimeter “DSC210” (from SeikoInstruments Inc.), 0.01 to 0.02 g of a sample was weighed in an aluminumpan, heated up to 200° C., and then cooled from that temperature to 0°C. at a temperature drop rate of 10° C./min. Next, the sample was heatedat a temperature rise rate of 10° C./min. The temperature at which anextension of the baseline below the endothermic highest peak temperaturewas intersected with a tangential line having a maximum inclination ofthe curve in the range of from a rise-up portion to an apex of the peakwas read as the glass transition temperature. When a peak is observed,the peak temperature is a glass transition temperature. When a peak isnot observed and a height difference is observed, the temperature atwhich a tangential line having a maximum inclination of the curve in theheight difference part is intersected with an extension of the baselineon the low-temperature side of the height difference is read as theglass transition temperature.

[Melting Point and Crystallinity Index of Resin]

Using a differential scanning calorimeter “Q-100” (from TA InstrumentsJapan Inc.), 0.01 to 0.02 g of a sample was weighed in an aluminum pan,and cooled from room temperature (20° C.) to 0° C. at a temperature droprate of 10° C./min. Next, the sample was left as such for 1 minute, andthen heated up to 180° C. at a temperature rise rate of 10° C./min tomeasure the quantity of heat. Among the observed endothermic peaks, thepeak temperature for the largest peak area is referred to as anendothermic highest peak temperature (1).

For a crystalline polyester, the endothermic highest peak temperature(1) is the melting point of the crystalline polyester.

According to (softening point (° C.))/(endothermic highest peaktemperature (1) (° C.)), the crystallinity index of the sample wascalculated.

[Acid Value of Resin]

The acid value of resin was measured according to the method describedin JIS K 0070-1992. In the method, however, the measurement solventalone was changed from the mixed solvent of ethanol and ether defined inJIS K 0070-1992 to a mixed solvent of acetone and toluene(acetone/toluene=1/1 (ratio by volume)).

[Melting Point of Releasing Agent]

Using a differential scanning calorimeter “Q-100” (from TA InstrumentsJapan Inc.), 0.02 g of a sample was weighed in an aluminum pan, heatedup to 200° C. and cooled from 200° C. to 0° C. at a temperature droprate of 10° C./min. Next, the same was heated at a temperature rise rateof 10° C./min, the quantity of heat was measured, and the endothermichighest peak temperature is referred to as a melting point of thesample.

[Volume Median Particle Diameter (D₅₀) of Resin Particles, ColorantParticles, Releasing Agent Particles, and Charge Control AgentParticles, and Dispersoid in Mixed Solution of Dispersion Containingthese Particles]

The volume median particle diameter (D₅₀) of resin particles, colorantparticles, releasing agent particles, and charge control agentparticles, and dispersoid in a mixed solution of a dispersion containingthese particles was measured by the following method.

-   -   (1) Measurement Device: Laser Diffraction-Type Particle Sizer        “LA-920” (from Horiba Ltd.)    -   (2) Measurement Conditions:

Distilled water was added to a measurement cell, and the volume medianparticle diameter (D₅₀) was measured at a concentration at which theabsorbance could falls within an appropriate range.

[Solid Concentration of Aqueous Dispersion, Colorant Dispersion,Releasing Agent Particle Dispersion, and Charge Control AgentDispersion]

Using an infrared moisture meter “FD-230” (from Kett ElectricLaboratory), 5 g of a sample was dried at a drying temperature of 150°C. under a measuring mode 96 (monitoring time: 2.5 minutes, moisturevariation range: 0.05%), and then subjected to measurement of a watercontent (% by mass) of the sample. The solid concentration wascalculated according to the following expression.Solid concentration (% by mass)=100−M

-   -   M: water content (% by mass) of sample        [Volume Median Particle Diameter (D₅₀) of Toner]

The volume median particle diameter (D₅₀) of toner was measured by thefollowing method.

-   -   Measurement device: “Coulter Multisizer (registered trademark)        III” (from Beckman Coulter Inc.)    -   Aperture diameter: 50 μm    -   Analyzing software: “Coulter Multisizer (registered trademark)        III Version 3.51” (from Beckman Coulter Inc.)    -   Electrolyte solution: “Isotone (registered trademark) II” (from        Beckman Coulter Inc.)        Dispersion:

“Emulgen (registered trademark) 109P” (polyoxyethylene lauryl ether,from Kao Corporation, HLB (hydrophile-lipophile balance, by Griffinmethod)=13.6) was dissolved in the above-mentioned electrolyte solutionto prepare a dispersion having a concentration of 5% by mass.

Dispersing Condition:

Ten milligrams of a sample to be measured were added to 5 mL of theaforementioned dispersion, and dispersed therein using an ultrasonicdisperser for 1 minute. Thereafter, 25 mL of the electrolyte solutionwas added to the resulting dispersion, and further dispersed using theultrasonic disperser for 1 minute to prepare a sample dispersion.

Measurement Condition:

The thus prepared dispersion and 100 mL of the electrolyte solution wereadded to a beaker, and after controlling the concentration of theresultant dispersion in the beaker so as to complete measurement ofparticle sizes of 30,000 particles within 20 seconds, the particle sizesof the 30,000 particles in the dispersion were measured under thiscondition, and the volume median particle diameter (D₅₀) of theparticles was determined from the resultant particle size distribution.

Production of Resin Production Examples A1 to A4, A21 to A22

(Synthesis of Amorphous Polyesters A-1 to A-4, A-21 to A-22)

The alcohol components, the carboxylic acid components excepttrimellitic anhydride and fumaric acid, the esterification catalyst andthe esterification promoter shown in Table 1 were put into a 10-Lfour-necked flask equipped with a thermometer, a stainless steelstirring bar, a dewatering tube with a falling type condenser, and anitrogen inlet tube. The contents of the flask were heated up to 180° C.in a mantle heater in a nitrogen atmosphere and further heated up to210° C. taking 5 hours. Thereafter, trimellitic anhydride and fumaricacid (fumaric acid was used in Production Examples A2, A4, A21 and A22)were put into the flask. The contents of the flask were heated up to220° C., and at 8.0 kPa, reacted until reaching the softening pointshown in Table 1 below to give amorphous polyesters A-1 to A-4, and A-21to A-22 of an amorphous resin (A).

TABLE 1 Production Production Production Production Example A1 ExampleA2 Example A3 Example A4 Amorphous Resin (A) A-1 A-2 A-3 A-4 [part by[part by [g] [part by [g] [part by [g] mol] *1 [g] mol] *1 mol] *1 mol]*1 Raw Material Alcohol BPA-PO 3674 50 7000 100 Monomers ComponentBPA-EO 3412 50 1,2-Propanediol 3595 100 2377 70 1,4-Butanediol 1206 30Acid Terephthalic 1987 57 1992 60 5497 70 4450 60 Component Acid FumaricAcid 116 5 259 5 Alkenylsuccinic 508 10 1135 10 Anhydride Trimellitic927 23 384 10 908 10 572 6.7 Anhydride [part by [part by [part by [partby [g] mass] *2 [g] mass] *2 [g] mass] *2 [g] mass] *2 EsterificationTin(II) 50 0.5 50 0.5 50 0.5 50 0.5 Catalyst Di(2-ethylhexanoate)Esterification Gallic Acid 5 0.05 5 0.05 5 0.05 5 0.05 PromoterProperties Softening Point [° C.] 124.8 118.2 121.8 126.8 GlassTransition 64.1 61.2 63.5 67.5 Temperature [° C.] Crystallinity Index1.9 1.9 1.9 1.9 Acid Value [mgKOH/g] 15.1 20.0 16.6 13.1 ProductionProduction Example A21 Example A22 Amorphous Resin (A) A-21 A-22 [partby [part by [g] mol] *1 [g] mol] *1 Raw Material Alcohol BPA-PO 5093 70Monomers Component BPA-EO 2027 30 1,2-Propanediol 2458 70 1,4-Butanediol1247 30 Acid Terephthalic 1898 55 4218 55 Component Acid Fumaric Acid121 5 161 3 Alkenylsuccinic 264 5 587 5 Anhydride Trimellitic 599 151330 15 Anhydride [part by [part by [g] mass] *2 [g] mass] *2Esterification Tin(II) 50 0.5 50 0.5 Catalyst Di(2-ethylhexanoate)Esterification Gallic Acid 5 0.05 5 0.05 Promoter Properties SofteningPoint [° C.] 120.0 123.5 Glass Transition 59.1 58.5 Temperature [° C.]Crystallinity Index 2.0 2.1 Fedors SP Value 10.9 11.6 Acid Value[mgKOH/g] 17.4 19.7 *1: This means part by mol of each monomerconstituting the raw material monomers based on 100 parts by mol of thealcohol components in the raw material monomers. *2: This means part bymol based on 100 parts by mass of the total amount of the raw materialmonomers.

Production Examples C1 to C5, C21 to C24

(Synthesis of Crystalline Polyesters C-1 to C-5, C-21 to C-24)

The alcohol component, the carboxylic acid component and theesterification catalyst shown in Table 2 were put into a 10-Lfour-necked flask equipped with a thermometer, a stainless steelstirring bar, a dewatering tube with a falling type condenser, and anitrogen inlet tube. The contents of the flask were heated up to 140° C.in a mantle heater in a nitrogen atmosphere and further heated up to200° C. taking 8 hours. Thereafter, at 8.0 kPa, the contents of theflask were reacted until reaching the softening point shown in Table 2below to give crystalline polyesters C-1 to C-5, C-21 to C-24 of acrystalline resin (C).

TABLE 2 Production Production Production Production Production ExampleC1 Example C2 Example C3 Example C4 Example C5 Crystalline Resin (C) C-1C-2 C-3 C-4 C-5 [part by [part by [part by [part by [part by [g] mol]*1[g] mol]*1 [g] mol]*1 [g] mol]*1 [g] mol]*1 Raw Alcohol1,12-Dodecanediol 4676 100 Material Component 1,10-Decanediol 4311 100Monomers 1,6-Hexanediol 3688 100 1,4-Butanediol 2586 100 Ethylene Glycol1938 100 Acid Dodecanedioic 5324 100 5689 100 Component Acid SebacicAcid 6313 100 Tetradecanedioic 7414 100 8063 100 Acid [part by [part by[part by [part by [part by [g] mass]*2 [g] mass]*2 [g] mass]*2 [g]mass]*2 [g] mass]*2 Esterification Tin(II) 50 0.5 50 0.5 50 0.5 50 0.550 0.5 Catalyst Di(2-ethylhexanoate) Properties Softening Point [° C.]93.4 77.4 86.8 92.5 95.8 Melting Point [° C.] 84.1 69.2 77.8 88.2 91.0Crystallinity Index 1.1 1.1 1.1 1.0 1.1 Acid Value [mgKOH/g] 13.0 13.510.9 15.5 18.2 Production Production Production Production Example C21Example C22 Example C23 Example C24 Crystalline Resin (C) C-21 C-22 C-23C-24 [part by [part by [part by [part by [g] mol]*1 [g] mol]*1 [g]mol]*1 [g] mol]*1 Raw Alcohol Ethylene Glycol 3443 100 2349 100 MaterialComponent 1,4-Butanediol 3516 100 Monomers 1,6-Hexanediol 5043 100 AcidSuccinic Acid 6558 100 Component Fumaric Acid 4957 100 Terephthalic 6484100 Acid Sebacic Acid 7652 100 [part by [part by [part by [part by [g]mass]*2 [g] mass]*2 [g] mass]*2 [g] mass]*2 Esterification Tin(II) 500.5 50 0.5 50 0.5 50 0.5 Catalyst Di(2-ethylhexanoate) PropertiesSoftening Point [° C.] 100.6 85.5 111.5 102.1 Melting point [° C.] 101.584.7 115.0 110.5 Crystallinity Index 1.0 1.0 1.0 0.9 Fedors SP Value11.7 10.2 11.9 10.6 Acid Value [mgKOH/g] 13.9 14.9 15.3 14.9 *1Thismeans part by mol of each monomer constituting the raw material monomersbased on 100 parts by mol of the alcohol components in the raw materialmonomers. *2This means part by mass based on 100 parts by mass of thetotal amount of the raw material monomers.

Production of Resin Composition (C-P) Production Example CP1

(Production of Resin Composition CP-1)

500 g of the crystalline polyester resin C-1 was put into a 2-Lfour-necked flask equipped with a thermometer, a stainless steelstirring bar, a dewatering tube with a falling type condenser, and anitrogen inlet tube. The contents of the flask were heated up to 150° C.in a mantle heater in a nitrogen atmosphere, and then 5 g of“Polyethyleneimine 300” (from Junsei Chemical Co., Ltd.) was addedthereto, and reacted at 150° C. for 3 hours to give a resin compositionCP-1 of a condensation product of the crystalline polyester C-1 and thepolyethyleneimine.

The acid value of the resultant resin composition CP-1 was 7.5 mgKOH/g.

Production Examples CP2 to CP5

(Production of Resin Compositions CP-2 to CP-5)

According to the same method as in Production Example CP1 except that,in Production Example CP1, the crystalline polyester C-1 was changed tocrystalline polyesters C-2 to C-5, resin compositions CP-2 to CP-5 ofcondensation products of the crystalline polyester C-2 to C-5 and thepolyethyleneimine were produced.

Production Example CP6

(Production of Resin Composition CP-6)

According to the same method as in Production Example CP1 except that,in Production Example CP1, the amount of “Polyethyleneimine 300” addedwas changed to 3 g, a resin composition CP-6 of a condensation productof the crystalline polyester C-1 and the polyethyleneimine was produced.

Production Example CP7

(Production of Resin Composition CP-7)

According to the same method as in Production Example CP1 except that,in Production Example CP1, the amount of “Polyethyleneimine 300” addedwas changed to 49.5 g, a resin composition CP-7 of a condensationproduct of the crystalline polyester C-1 and the polyethyleneimine wasproduced.

Production Example CP8

(Production of Resin Composition CP-8)

According to the same method as in Production Example CP1 except that,in Production Example CP1, “Polyethyleneimine 300” was changed to“Polyethyleneimine 1800” (from Junsei Chemical Co., Ltd.), a resincomposition CP-8 of a condensation product of the crystalline polyesterC-1 and the polyethyleneimine was produced.

Production Examples CP21 to CP27

(Production of Resin Compositions CP-21 to CP-27)

According to the same method as in Production Example CP1 except that,in Production Example CP1, the kind and the added amount of thepolyethyleneimine were changed as in Table 3, resin compositions CP-21to CP-27 of condensation products of the resin (C) and thepolyethyleneimine were produced.

TABLE 3 Production Example CP1 CP2 CP3 CP4 CP5 CP6 CP7 CP8 ResinComposition (C-P) CP-1 CP-2 CP-3 CP-4 CP-5 CP-6 CP-7 CP-8 Resin (C) KindC-1 C-2 C-3 C-4 C-5 C-1 C-1 C-1 Amount (g) 500 500 500 500 500 500 500500 Polyethyleneimine Kind*1 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300PEI-300 PEI-300 PEI-1800 Amount (g) 5 5 5 5 5 3 49.5 5 ProductionExample CP21 CP22 CP23 CP24 CP25 CP26 CP27 Resin Composition (C-P) CP-21CP-22 CP-23 CP-24 CP-25 CP-26 CP-27 Resin (C) Kind C-21 C-22 C-23 C-24C-21 C-21 C-21 Amount (g) 500 500 500 500 500 500 500 PolyethyleneimineKind*1 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-1800 Amount(g) 5 5 5 5 3 49.5 5 *1PEI-300: “Polyethyleneimine 300” (from JunseiChemical Co., Ltd., Mn: 1500, Mw: 1800) PEI-1800: “Polyethyleneimine1800” (from Junsei Chemical Co., Ltd., Mn: 4400, Mw: 5300)

Production of Toner of First Embodiment Example 1

90 parts by mass of the amorphous polyester A-1, 10 parts by mass of theresin composition CP-1, 4 parts by mass of a colorant “Pigment Blue15:3” (from Dainichiseika Color & Chemicals Mfg. Co., Ltd.), 0.85 partsby mass of a negatively-chargeable charge control agent “BONTRON(registered trademark) E-81” (from Orient Chemical Industries Co.,Ltd.), and 2 parts by mass of a releasing agent “Mitsui Hi-Wax NP056”(polypropylene wax, from Mitsui Chemicals, Inc., melting point 124° C.)were uniformly mixed in a Henschel mixer to give a raw material mixturecontaining a binder resin composition for toner. Using a co-rotationtwin-screw extruder, the resultant composition was melt-kneaded at ascrew rotation speed of 200 r/min and at a barrel preset temperature of100° C. to give a melt-kneaded product. The resultant melt-kneadedproduct was cooled, roughly pulverized, then milled with a jet mill, andclassified to give toner particles having a volume median particlediameter (D₅₀) of 8.0 μm.

1.0 part by mass of a hydrophobic silica “NAX-50” (from Nippon AerosilCo., Ltd., hydrophobizing agent: hexamethyldisilazane, volume medianparticle diameter (D₅₀): 30 nm) was added to 100 parts by mass of theresultant toner particles, and mixed in a Henschel mixer to give a toner1.

The resultant toner 1 was evaluated according to the methods describedbelow.

Examples 2 to 13

Toners 2 to 13 were produced in the same manner as in Example 1, exceptthat the kind and the added amount of the amorphous polyester and theresin composition were changed as in Tables 4 to 5.

The resultant toners were evaluated according to the methods describedbelow.

Example 14

A toner 14 was produced in the same manner as in Example 1, except that,in Example 1, the amorphous polyester A-1 was changed to astyrene-acrylic resin “Joncryl (registered trademark) 611” (from BASFSE, softening point 112° C., glass transition temperature 50° C.,crystallinity index 2.2, acid value 53 mgKOH/g).

The resultant toner 14 was evaluated according to the methods describedbelow.

Example 15

A toner 15 was produced in the same manner as in Example 1, except that,in Example 1, the co-rotation twin-screw extruder for use formelt-kneading the resultant raw material mixture was changed to acontinuous two-open roll kneader “Kneadex” (from NIPPON COKE &ENGINEERING CO., LTD., roll outer diameter: 14 cm, effective rolllength: 80 cm) to give a melt-kneaded product.

Regarding the operation condition for the continuous two-open rollkneader, the high-rotation side roll (front roll) rotation number was 75r/min (peripheral speed 32.97 m/min), the low-rotation side roll (backroll) rotation number was 50 r/min (peripheral speed 21.98 m/min), andthe roll clearance on the melt kneaded product supply port side end was0.1 mm. Regarding the heating medium temperature and the cooling mediumtemperature inside the roll, the raw material mixture supply port sideof the high-rotation side roll was 135° C., and the melt-kneaded productdischarge port side thereof was 90° C.; and the raw material mixturesupply port side of the low-rotation side roll was 35° C., and themelt-kneaded product discharge port side thereof was 35° C. The rawmaterial mixture feeding speed was 10 kg/hr, and the average residencetime was about 6 minutes.

The resultant melt-kneaded product was cooled, roughly pulverized, thenmilled with a jet mill, and classified to give toner particles having avolume median particle diameter (D₅₀) of 8.0 μm.

1.0 part by mass of a hydrophobic silica “NAX-50” (from Nippon AerosilCo., Ltd., hydrophobizing agent: hexamethyldisilazane, volume medianparticle diameter (D₅₀): 30 nm) was added to 100 parts by mass of theresultant toner particles, and mixed in a Henschel mixer to give a toner15.

The resultant toner 15 was evaluated according to the methods describedbelow.

Example 16

(Production of Aqueous Dispersion of Binder Resin Particles)

90 g of the amorphous polyester A-1, 10 g of the resin composition CP-1,60 g of methyl ethyl ketone, and 16.7 g (4.5 parts by mass relative to100 parts by mass of binder resin composition) of an anionic surfactant“Emal (registered trademark) E27C (sodium polyoxyethylene lauryl ethersulfate: solid content 27% by mass)” (from Kao Corporation) were putinto a 3-L vessel equipped with a stirrer, a reflux condenser, adropping funnel, a thermometer and a nitrogen inlet tube, and dissolvedat 73° C., taking 2 hours. An aqueous 5 mass % sodium hydroxide solutionwas added to the resultant solution so as to have a neutralizationdegree of 70 mol % relative to the weighted average acid value of theacid value of the amorphous polyester A-1 and the acid value of theresin composition CP-1, and stirred for 30 minutes.

This was kept stirred at 280 r/min (peripheral speed 88 m/min) still at73° C., and 675 g of ion-exchanged water was added thereto, taking 77minutes, for phase inversion emulsification. Still continuously kept at73° C., methyl ethyl ketone was evaporated away under reduced pressure.Subsequently, with stirring at 280 r/min (peripheral speed 88 m/min),the dispersion was cooled to 30° C. Subsequently, the solidconcentration of the dispersion was measured, and ion-exchanged waterwas added thereto so that the solid concentration thereof could be 20%by mass, thereby producing an aqueous dispersion of binder resinparticles dispersed in an aqueous medium.

(Production of Colorant Dispersion)

50 g of copper phthalocyanine “ECB-301” (from Dainichiseika Color &Chemicals Mfg. Co., Ltd.), 5 g of a nonionic surfactant “EMULGEN 150”(polyoxyethylene lauryl ether, from Kao Corporation) and 200 g ofion-exchanged water were mixed and dispersed using a homogenizer for 10minutes to give a colorant dispersion containing colorant particles. Thevolume median particle diameter (D₅₀) of the colorant particles was 120nm, and the solid concentration was 22% by mass.

(Production of Releasing Agent Particle Dispersion)

50 g of paraffin wax “HNP9 (from Nippon Seiro Co., Ltd., melting point85° C.), 5 g of a cationic surfactant “Sanisol (registered trademark)B50” (from Kao Corporation, alkylbenzyldimethylammonium chloride) and200 g of ion-exchanged water were heated at 95° C., and dispersed usingan ultrasonic homogenizer (from Doctor Hielscher GmbH, trade name:“UP-400S”) at an output power of 350 W for 30 minutes to give areleasing agent dispersion containing releasing agent particles. Thevolume median particle diameter (D₅₀) of the paraffin wax (releasingagent particles) was 550 nm, and the solid concentration was 22% bymass.

(Production of Charge Control Agent Dispersion)

50 g of a salicylic acid-based compound “BONTRON (registered trademark)E-84” as a charge control agent (from Orient Chemical Industries Co.,Ltd.), 5 g of a nonionic surfactant “EMULGEN 150” (from Kao Corporation)and 200 g of ion-exchanged water were mixed, and dispersed with glassbeads using a sand grinder for 10 minutes to give a charge control agentdispersion containing charge control agent particles. The volume medianparticle diameter (D₅₀) of the charge control agent particles was 400nm, and the solid concentration was 22% by mass.

(Production of Toner 16)

300 g of the aqueous dispersion of binder resin particles, 8 g of thecolorant dispersion, 20 g of the releasing agent dispersion, 2 g of thecharge control agent dispersion and 52 g of deionized water were putinto a 2-L vessel, and with stirring with an anchor-type stirrer at 100r/min (peripheral speed 31 m/min) at 20° C., 150 g of an aqueous 0.1mass % calcium chloride solution was dropwise added thereto, taking 30minutes. Subsequently, the resultant mixture was heated up to 50° C.with stirring, and kept at 50° C. After the volume median particlediameter (D₅₀) of the dispersoid in the mixture was confirmed to havereached 8.2 μm, a diluted liquid of 4.2 g of an anionic surfactant “EMAL(registered trademark) E27C” (from Kao Corporation, solid content 27% bymass) as an aggregation stopping agent, as diluted with 37 g ofdeionized water, was added thereto. Next, the mixture added with thediluted liquid was heated up to 80° C., and from the time at which themixture reached 80° C., the mixture was kept at 80° C. for 1 hour, andthus the heating was ended. After coalesced particles were formedaccording to the operation, the system was gradually cooled down to 20°C., then filtered through a 150-mesh (150-μm opening) wire cloth,further filtered under suction, washed and dried to give tonerparticles. The volume median particle diameter (D₅₀) of the tonerparticles was 8.0 μm.

1.0 part by mass of hydrophobic silica “NAX-50” (from Nippon AerosilCo., Ltd., hydrophobizing agent: hexamethyldisilazane, volume medianparticle diameter (D₅₀): 30 nm) was added to 100 parts by mass of theresultant toner particles, and mixed in a Henschel mixer to give a toner16.

The resultant toner 16 was evaluated according to the methods describedbelow.

Comparative Example 1

A toner 17 was produced in the same manner as in Example 1, except thatin Example 1, the resin composition CP-1 was changed to the crystallinepolyester C-1. The resultant toner 17 was evaluated according to themethods described below.

Comparative Example 2

A toner 18 was produced in the same manner as in Example 2, except thatin Example 2, the resin composition CP-2 was changed to the crystallinepolyester C-2. The resultant toner 18 was evaluated according to themethods described below.

Comparative Example 3

Toner particles were formed in the same manner as in Comparative Example1, and 50 parts by mass of the toner particles and 450 parts by mass ofpure water were put into a disposable cup and dispersed by stirring withan ultrasonic homogenizer. The particles were made to have a pH 2.5 with0.3 M nitric acid added thereto, and then “Polyethyleneimine 300” wasadded thereto so as to be 0.1% by mass relative to the toner particles,and stirred for 1 hour. This was filtered under suction, and theresultant cake was washed with 1,500 parts by mass of pure water to givea washed cake. The washed cake was dried at 40° C. for 40 hours to givea toner 19. The resultant toner 19 was evaluated according to themethods described below.

Comparative Example 4

A toner 20 was produced in the same manner as in Example 1, except thatin Example 1, the resin composition CP-1 was not added and a chargecontrol agent “Polyethyleneimine 300” was added so as to be 0.1% by massin the toner. The resultant toner 20 was evaluated according to themethods described below.

[Evaluation of Toner]

<Low-Temperature Fusing Property>

The toner was loaded into a copying machine “AR-505” (from SharpCorporation), in which the fusing unit had been reformed so as to befusable outside the machine, and unfused images (printing area: 3 cm×4cm; amount of toner deposited: 0.45 mg/cm²) were printed on paper “CopyBond SF-70NA (75 g/m²)” from Sharp Corporation. Subsequently, using afusing unit controlled to give a total fusing pressure of 40 kgf (fusingspeed 390 mm/sec), and elevating the temperature of the fusing rollerfrom 100° C. up to 200° C. successively at intervals of 5° C., theunfused prints were printed at each temperature as a fusing test. Anadhesive cellophane tape (Unisef Cellophane (from Mitsubishi Pencil Co.,Ltd., width: 18 mm, JIS Z1522) was stuck to the image of the fusedprint, then led to pass through a fusing roller set at 30° C., and theadhesive cellophane tape was peeled. The reflection image density in theimage part before the adhesive cellophane tape had been stuck thereto,and the reflection image density of the image part after the adhesivecellophane tape had been peeled were measured using a reflectiondensitometer “RD-915” (from GretagMachbeth Company), and the temperatureof the fusing roller at which the ratio of the two (reflection imagedensity after tape peeling/reflection image density before tapesticking)×100) has first exceeded 90% is referred to as a lowest fusingtemperature. When the lowest fusing temperature is lower, thelow-temperature fusing property of the toner is better.

<Storage Stability>

4 g of the toner was left in an environment at a temperature of 50° C.and a relative humidity of 60% for 72 hours. After thus left, the degreeof toner aggregation occurrence was visually checked, and the storagestability of the toner was evaluated according to the followingevaluation criteria.

<Evaluation Criteria>

-   -   A: Even after 72 hours, no aggregation was recognized.    -   B: After 48 hours, no aggregation was recognized, but after 72        hours, some aggregation was recognized.    -   C: After 24 hours, aggregation was not recognized, but after 48        hours, some aggregation was recognized.    -   D: Within 24 hours, aggregation was already recognized.        <Durability>

The toner was charged into a nonmagnetic one-component developingmachine “MicroLine 5400” (from Oki Data Corporation), and tested in aprinting durability test at a coverage rate of 0.3% and a printing speedof 300 sheets per hour, in an environment at a temperature of 35° C. anda relative humidity of 50%. The test is a continuous printing durabilitytest, in which a solid image was printed once every hour, and checkedfor appearance of white streaks caused by toner filming on blades toevaluate printing durability. The test was stopped just when whitestreaks were confirmed to appear, and continued for at most 10 hours.Slower appearance of white streaks means more excellent durability.Specifically, a longer time shown in Tables 4 to 6 below means moreexcellent toner durability.

TABLE 4 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6Example 7 Example 8 Toner No. 1 2 3 4 5 6 7 8 Amorphous Resin (A)  A-1 A-1  A-1  A-1  A-1  A-2  A-3  A-4 Resin Composition (C-P) CP-1 CP-2CP-3 CP-4 CP-5 CP-1 CP-1 CP-1 Proportion of 0.1 0.1 0.1 0.1 0.1 0.1 0.10.1 Polyethyleneimine [mass %]*3 Polyethyleneimine PEI-300 PEI-300PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 (A)/(C-P) 90/10 90/1090/10 90/10 90/10 90/10 90/10 90/10 [ratio by mass] Evaluation LowestFusing 130 130 130 130 130 130 130 135 Results Temperature [° C.]Storage Stability A A A A A B B A Durability [hr] 10 9 9 9 9 9 8 10*3Blending amount relative to the total amount of the resin composition(C-P) and the amorphous resin (A)

TABLE 5 Example Example Example Example Example Example Example Example9 10 11 12 13 14 15*5 16 *6 Toner No. 9 10 11 12 13 14 15 16 Amorphous A-1  A-1  A-1  A-1  A-1 St-Ac  A-1  A-1 Resin (A) *4 Resin CP-1 CP-1CP-6 CP-7 CP-8 CP-1 CP-1 CP-1 Composition (C-P) Proportion of 0.3 0.070.06 0.9 0.1 0.1 0.1 0.1 Polyethyleneimine [mass %]*3 PolyethyleneiminePEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300 PEI-300(A)/(C-P) 70/30 93/7 90/10 90/10 90/10 90/10 90/10 90/10 [ratio by mass]Evaluation Lowest Fusing 130 140 135 135 135 135 130 135 ResultsTemperature [° C.] Storage Stability B A B B A C B B Durability [hr] 710 8 9 8 6 10 9 *3Blending amount relative to the total amount of theresin composition (C-P) and the amorphous resin (A) *4Styrene-acrylicresin “Joncryl 611” *5Melt-kneading in a roll kneader (in Examples 1 to14, and Comparative Examples 1 and 2, melt-kneading in a twin-screwextruder) *6Aggregating and coalescing method

TABLE 6 Compar- Compar- Compar- Compar- ative ative ative ative Example1 Example 2 Example 3 Example 4 Toner No. 17  18   19  20 AmorphousResin (A) A-1 A-1 A-1 A-1 Crystalline Resin (C) C-1 C-2 C-1 Proportionof 0 0    0.1    0.1 Polyethyleneimine [mass %]*7 Polyethyleneimine — —PEI-300 PEI-300 (A)/(C) 90/10 90/10 90/10 100/0 [ratio by mass]Evaluation Lowest 145  145  145 160 Results Fusing Temperature [° C.]Storage D D D B Stability Durability 3 2  3  9 [hr] *7Blending amountrelative to the total amount of the binder resin

As shown in Tables 4 and 5, it is known that the toners 1 to 16 fordeveloping electrostatic images (Examples 1 to 16) each containing abinder resin composition for toner containing a resin composition (C-P)prepared by condensing an acid group-having crystalline resin (C) and apolyethyleneimine, and an amorphous resin (A) are excellent in alllow-temperature fusing property, storage stability and durability.

As opposed to these, as shown in Table 6, it is known that the toners 17and 18 for developing electrostatic images (Comparative Examples 1 and2) not containing a resin composition (C-P) prepared by condensing anacid group-having crystalline resin (C) and a polyethyleneimine butcontaining, in place of it, a binder resin composition for tonercontaining an acid group-having crystalline resin (C), as well as thetoner 19 for developing electrostatic images (Comparative Example 3) notcontaining a resin composition (C-P) prepared by condensing an acidgroup-having crystalline resin (C) and a polyethyleneimine butcontaining, in place of it, a binder resin composition for tonercontaining an acid group-having crystalline resin (C), and containing apolyethyleneimine as an external additive are all inferior to the toners1 to 16 of Examples in point of low-temperature fusing property, storagestability and durability, and further, the toner 20 for developingelectrostatic images (Comparative Example 4) prepared by adding apolyethyleneimine as a charge control agent to a binder resincomposition for toner containing neither a resin composition (C-P)prepared by condensing an acid group-having crystalline resin (C) and apolyethyleneimine nor an acid group-having crystalline resin (C) isinferior to the toners 1 to 16 of Examples in point of low-temperaturefusing property.

Production of Toner of Second Embodiment Example 21

90 parts by mass of the amorphous polyester A-21, 10 parts by mass ofthe resin composition CP-21, 4 parts by mass of a colorant “Pigment Blue15:3” (from Dainichiseika Color & Chemicals Mfg. Co., Ltd.), 0.85 partsby mass of a negatively-chargeable charge control agent “BONTRON(registered trademark) E-81” (from Orient Chemical Industries Co.,Ltd.), and 2 parts by mass of a releasing agent “Mitsui Hi-Wax NP056”(polypropylene wax, from Mitsui Chemicals, Inc., melting point 124° C.)were uniformly mixed in a Henschel mixer to give a raw material mixturecontaining a binder resin composition for toner. Using a co-rotationtwin-screw extruder, the resultant composition was melt-kneaded at ascrew rotation speed of 200 r/min and at a barrel preset temperature of100° C. to give a melt-kneaded product. The resultant melt-kneadedproduct was cooled, roughly pulverized, then milled with a jet mill, andclassified to give toner particles having a volume median particlediameter (D₅₀) of 8.0 μm.

1.0 part by mass of a hydrophobic silica “NAX-50” (from Nippon AerosilCo., Ltd., hydrophobizing agent: hexamethyldisilazane, volume medianparticle diameter (D₅₀): 30 nm) was added to 100 parts by mass of theresultant toner particles, and mixed in a Henschel mixer to give a toner21.

The resultant toner 21 was evaluated according to the methods describedbelow.

Examples 22 to 30

Toners 22 to 30 were produced in the same manner as in Example 21,except that the kind and the added amount of the amorphous polyester andthe resin composition were changed as in Table 7.

The resultant toners were evaluated according to the methods describedbelow.

Comparative Examples 21 to 22

Toners 31 and 32 were produced in the same manner as in Example 21,except that in Example 21, the resin composition CP-21 was changed tothe crystalline polyester shown in Table 7. The resultant toners 31 and32 were evaluated according to the methods described below.

[Evaluation of Toner]

<Low-Temperature Fusing Property>

Immediately after production, the toner was evaluated according to theabove-mentioned evaluation method for low-temperature fusing property.The resultant lowest fusing temperature is referred to as a lowestfusing temperature (T1).

Aging Stability of Low-Temperature Fusing Property

The toner was stored in a constant-temperature bath at a temperature of40° C. for 3 days, and then evaluated for the lowest fusing temperature(T2) according to the same method as that for the above-mentionedlow-temperature fusing property evaluation. A difference between T2 andT1 (T2−T1) was calculated to evaluate the aging stability oflow-temperature fusing property.

<Charge Property after Long-Term Storage>

The toner was stored in an environment at a temperature of 40° C. and arelative humidity of 60% for 3 days, and then 0.6 g of the toner and19.4 g of a silicon ferrite carrier (from Kanto Denka Kogyo Co., Ltd.,average particle size: 90 μm) were put into a 50-mL polyethylene vessel,mixed at 250 r/min using a ball mill, and after mixed for 3600 seconds,the electric charge amount of the toner was measured using a Q/M meter(from EPPING GmbH) according to the following method.

After mixed, a regulated amount of the mixture of the toner and thecarrier was put into the cell attached to the Q/M meter, and the toneralone was sucked for 90 seconds through a sieve having an opening of 32μm (stainless, twill weave, wire diameter: 0.0035 mm). The voltagechange on the carrier generated at that time was monitored, and a valueof [total electric amount after 90 seconds (μC)/sucked toner amount (g)]was referred to as the electric charge amount of the toner (μC/g).

[Evaluation Criteria]

-   -   A: Electric charge amount 40 μC/g or more    -   B: Electric charge amount 30 μC/g or more and less than 40 μC/g    -   C: Electric charge amount 20 μC/g or more and less than 30 μC/g    -   D: Electric charge amount 10 μC/g or more and less than 20 μC/g    -   E: Electric charge amount less than 10 μC/g

TABLE 7 Example Example Example Example Example Example Example 21 22 2324 25 26 27 Toner No. 21 22 23 24 25 26 27 Amorphous Resin (A) A-21 A-21A-21 A-21 A-22 A-21 A-21 Resin Composition Kind CP-21  CP-22  CP-23 CP-24  CP-24  CP-24  CP-24  (C-P)/Crystalline Resin (C) C-21 C-22 C-23C-24 C-24 C-24 C-24 Resin Polyethyleneimine PEI-300 PEI-300 PEI-300PEI-300 PEI-300 PEI-300 PEI-300 Proportion of 0.1 0.1 0.1 0.1 0.1 0.30.07 Polyethyleneimine [mass %]*1 (A)/(C-P) 90/10 90/10 90/10 90/1090/10 70/30 93/7 [ratio by mass] ΔSP [(cal/cm³)^(1/2)] *2 0.8 0.7 1.00.3 1.0 0.3 0.3 Evaluation Lowest Fusing 125 125 130 120 130 120 130Results Temperature T₁ [° C.] Aging Stability of 10 5 10 5 10 20 5Low-Temperature Fusing Property [° C.] Charge Property after B B B A C DA long-term storage Example Example Example Comparative Comparative 2829 30 Example 21 Example 22 Toner No. 28 29 30 31 32 Amorphous Resin (A)A-21 A-21 A-21 A-21 A-21 Resin Composition Kind CP-25  CP-26  CP-27 C-22 C-24 (C-P)/Crystalline Resin (C) C-21 C-21 C-21 — — ResinPolyethyleneimine PEI-300 PEI-300 PEI-1800 — — Proportion of 0.06 0.90.1 — — Polyethyleneimine [mass %]*1 (A)/(C-P) 90/10 90/10 90/10 — —[ratio by mass] ΔSP [(cal/cm³)^(1/2)] *2 0.3 0.3 0.3 0.7 0.3 EvaluationLowest Fusing 120 120 130 130 120 Results Temperature T₁ [° C.] AgingStability of 25 15 20 40 40 Low-Temperature Fusing Property [° C.]Charge Property after C D C E E long-term storage *1Blending amountrelative to the total amount of the resin composition (C-P) and theamorphous resin (A) *2: Difference in Fedors SP value between thecrystalline resin (C) and the amorphous resin (A)

As shown in Table 7, it is known that the toners 21 to 30 for developingelectrostatic images (Examples 21 to 30) each containing a binder resincomposition for toner, which contains a resin composition (C-P) preparedby condensing an acid group-having crystalline resin (C) and apolyethyleneimine, and an amorphous resin (A) and in which thedifference in a Fedors SP value between the crystalline resin (C) andthe amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or less, are excellent inall low-temperature fusing property, aging stability of low-temperaturefusing property and charge property after storage.

As opposed to these, it is known that the toners 31 and 32 fordeveloping electrostatic images (Comparative Examples 21 and 22)containing a binder resin composition for toner that does not contain aresin composition (C-P) prepared by condensing an acid group-havingcrystalline resin (C) and a polyethyleneimine but contains, in place ofit, an acid group-having crystalline resin (C) are inferior to thetoners 21 to 30 of Examples in point of aging stability oflow-temperature fusing property and charge property after storage.

The invention claimed is:
 1. A toner for developing electrostatic imagescomprising a binder resin composition, wherein the binder resincomposition comprises: a resin composition (C-P) prepared by condensingan acid group-having crystalline resin (C) and a polyalkyleneimine; andan amorphous resin (A), wherein the acid group-having crystalline resin(C) is a crystalline polyester-based resin being a polycondensate of analcohol component (c-al) and a carboxylic acid component (c-ac), inwhich the alcohol component (c-al) comprises an α,ω-aliphatic diolhaving 2 to 16 carbon atoms, and the carboxylic acid component (c-ac)comprises an α,ω-aliphatic dicarboxylic acid having 4 to 14 carbonatoms.
 2. The toner according to claim 1, wherein a difference in aFedors solubility parameter (SP value) between the crystalline resin (C)and the amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or less.
 3. The toneraccording to claim 1, wherein a ratio by mass of the amorphous resin (A)to the resin composition (C-P) [(A)/(C-P)] is from 65/35 to 95/5.
 4. Thetoner according to claim 1, wherein a proportion of thepolyalkyleneimine is from 0.05% by mass to 1% by mass relative to atotal amount of the resin composition (C-P) and the amorphous resin (A).5. The toner according to claim 1, wherein a number-average molecularweight of the polyalkyleneimine is from 800 to 5,000.
 6. A method forproducing a toner for developing electrostatic images comprising abinder resin composition, the method comprising adding the binder resincomposition to raw materials of the toner, wherein the binder resincomposition is prepared by the method comprising: condensing an acidgroup-having crystalline resin (C) and a polyalkyleneimine to obtain aresin composition (C-P); and mixing the resin composition (C-P) and anamorphous resin (A), wherein the acid group-having crystalline resin (C)is a crystalline polyester-based resin being a polycondensate of analcohol component (c-al) and a carboxylic acid component (c-ac), inwhich the alcohol component (c-al) comprises an α,ω-aliphatic diolhaving 2 to 16 carbon atoms, and the carboxylic acid component (c-ac)comprises an α,ω-aliphatic dicarboxylic acid having 4 to 14 carbonatoms.
 7. The method according to claim 6, wherein a difference in aFedors solubility parameter (SP value) between the crystalline resin (C)and the amorphous resin (A) is 1.3 (cal/cm³)^(1/2) or less.
 8. Themethod according to claim 6, wherein a ratio by mass of the amorphousresin (A) to the resin composition (C-P) [(A)/(C-P)] is from 65/35 to95/5.
 9. The toner according to claim 1, wherein the acid group-havingcrystalline resin (C) is a crystalline polyester, a crystallinecomposite resin having a polyester segment and a vinylic resin segment,or a combination thereof.
 10. The toner according to claim 1, whereinthe amorphous resin (A) is at least one resin selected from the groupconsisting of an amorphous polyester resin and a styrene-acrylic resin,wherein the amorphous polyester resin is an amorphous polyester or anamorphous composite resin having a polyester segment and a vinylic resinsegment.
 11. The toner according to claim 1, wherein a SP value of thecrystalline resin (C) is from 9.5 (cal/cm³)^(1/2) to 12.5(cal/cm³)^(1/2).
 12. The method according to claim 6, wherein thecondensing is performed for at least 10 minutes.
 13. The methodaccording to claim 6, wherein an amount of the polyalkyleneimine used inthe condensing is from 0.05% by mass to 1% by mass relative to a totalamount of the resultant resin composition (C-P) and the amorphous resin(A).
 14. The toner according to claim 1, wherein the melting point ofthe acid group-having crystalline resin (C) is from 50° C. to 130° C.15. The toner according to claim 1, wherein the alcohol component (c-al)is at least one selected from the group consisting of ethylene glycol,1,4-butanediol, 1,6-hexanediol, 1,10-decanediol and 1,12-dodecanediol.16. The toner according to claim 1, wherein the carboxylic acidcomponent (c-ac) is at least one selected from the group consisting ofsebacic acid, dodecanedioic acid, and tetradecanedioic acid.
 17. Thetoner according to claim 1, wherein the carboxylic acid component (c-ac)is at least one selected from the group consisting of succinic acid,fumaric acid, and sebacic acid.
 18. The toner according to claim 1,wherein the carboxylic acid component (c-ac) comprises an α,ω-aliphaticdicarboxylic acid having 10 to 14 carbon atoms.
 19. The method accordingto claim 6, wherein the carboxylic acid component (c-ac) comprises anα,ω-aliphatic dicarboxylic acid having 10 to 14 carbon atoms.
 20. Themethod according to claim 6, wherein the amorphous resin (A) is at leastone resin selected from the group consisting of an amorphous polyesterresin and a styrene-acrylic resin, wherein the amorphous polyester resinis an amorphous polyester or an amorphous composite resin comprising apolyester segment and a vinylic resin segment.
 21. The method accordingto claim 6, wherein a number-average molecular weight of thepolyalkyleneimine is from 800 to 5,000.